Text

FENOC-Davis-Besse Nuclear Power Station, Unit 1 Docket No. 50-346, License No. NPF-3 Submittal of Contractor Root Cause Assessment Report-Section 4
	ML12138A067
Person / Time
Site:	Davis Besse
Issue date:	05/14/2012
From:	; FirstEnergy Nuclear Operating Co
To:	; NRC/RGN-III
References
	L-12-196 ACI 546R-04
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	v • d • e

{{#Wiki_filter:Exhibit 22 .******************3

ACI 546R-04: .................

Concrete Repair Guide: * . Reported by ACI Committee 546 JayH. Paul Chair James P. Barlow YelenaS. Golod Paul D. Carter Harald G. Greve Michael M. Chehab Robert F. Joyce Marwan A. Daye Lawrence F. Kahn Floyd E. Dimmick Brian F. Keane Peter H. Emmons Benjamin Lavon Michael 1. Garlich Kenneth M Lozen Steven H Gebler James E. McDonald I. Lenn Glassgold This document provides guidance on the selection and application of maJerials and metlwds for the repair, protection, and strengthening qf concrete structures. An overview of maJeria/s and methods is presented as a guide for making a selection for a particular application References are provided for obtaining in-depth iliformation on the selected materials or metlwds. Keywords: anchordge; cementitious; coating; concrete; joint sealant; placement; pdymcr; reinforcement; repair. ACI Committee Reports, Guides, Standard Practices, and Commentaries are intended for guidance in planning, designing, executing, and inspecting construction. This document is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who v,ill accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all responsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom. Reference to this document shall not be made in contract documents. Ifitems found in this document are desired by the ArchitectlEngineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the ArchitectlEngineer. It is the responsibility of the user of this document to establish health and safety practices appropriate to the specific circumstances involved with its use. ACI does not make any representations with regard to health and safety issues and the use of this document. Ibe user must determine the applicability of all regulatory limitations before applying the document and must comply with all applicable laws and regulations, including but not limited to, United States Occupational Safety and Health Administration (OSHA) health and safety standards. Paul E. Kevin A. Michols Joe Richard Montani Michael M. Myles A. Murray Ronald R Thomas 1. Pasko GeOIge I. DonT. Pyle Alexander Richard C. Reed D. Gerald Johan 1. Silfwerbrand Patrick M W. Glenn Smoak Mark V. Ziegler Chapter 1-lntroductlon, p. U-Use ofthis 1.3-Repair 1.4-Design 1.5-Format and Chapter 2-Concrete removal, preparation, repair techniques, p. 2.1-Introduction and general 2.2--Concrete 2.3-Surface 2.4-Reinforcement 2.5-Anchorage methods and 2.6-Materials placement for various repair 2.7-Bonding Chapter 3-Repair materials, p. 546R*20 3.2--Cementitious 3.3-Polymer 3.4-Bonding 3.5--Coatings on 3.7-Material -Q4 supersedes ACI 546R*96 and became effective September 23, _ C 2004, American Concrete reserved including rights of reproduction and use in any form or by means, including the making of copies by any photo process, or by electronic mechanical device, printed, written, or oral, or recording for sound or viSWli tion or for use in any know etrieval system or device, unless permission writing is obtained from 663 Page 1 of 8 664 Exhibit 22 CONCRETE REPAIR MANUAL Chapter 4-Protective systems, p. 546R-30 4. I-Introduction and selection factors 4.2-Concrete surface preparation and installation requirements 4.3-Typical selection problems 4.4--Systems concept 4.5-Surface treatments 4.6-Joint sealants 4.7-Cathodic protection 4.8-Chloride extraction 4.9-Realkalization Chapter S-Strengthening techniques, p. 546R-41 5.I-General 5.2-Internal structural repair (restoration to original member strength) 5.3-Interior reinforcement 5.4--Exterior reinforcement (encased and exposed) 5.5-Exterior post-tensioning 5.6-Jackets and collars 5.7-Supplemental members 5.8-Repair of concrete columns 5.9-Column repair parameters Chapter 6-References, p. 546R-48 6. I-Referenced standards and 6.2-Cited CHAPTER 1-INTROOUCTION 1.1-Use of this document This document provides guidance on selection of materials and application methods for the repair, protection, and strengthening of concrete structures. The information is applicable to repairing damaged or deteriorated concrete structures, correcting design or construction deficiencies, or upgrading a structure for new uses or to meet more restrictive building codes. This guide summarizes current practices in concrete repair and provides sufficient information for the initial planning of repair work and for selecting suitable repair materials and application methods for specific conditions. Many of the topics covered in this guide are more extensively covered in other ACI committee documents. Readers of this guide should refer to the appropriate documents of other ACI committees and other industry resources for additional information. 1.2-0efinitions corrosion-destruction of metal by chemical, chemical, or electrolytic reaction within its environment. dampproofing-treatm ent of concrete or mortar to retard the passage or absorption of water, or water vapor, either by application of a suitable admixture or treated cement, or by use of preformed film, such as polyethylene sheets, placed on grade before placing a slab. excavation-steps taken to remove deteriorated concrete, sound concrete, or both, designated for removal. non structural repair-a repair that addresses local deterioration and is not intended to affect the structural capacity ofamember. protection-the procedure of shielding the concrete ture from environmental and other damage for the purpose of preserving the structure or prolonging its useful life. repair-to replace or correct deteriorated, damaged, or faulty materials, components, or elements ofa structure. repair systems-the combination of materials and techniques used in the repair of a structure. strengthening-the process of restoring the capacity of damaged components of structural concrete to its original design capacity, or increasing the strength of structural concrete. structural repair-a repair that re-establishes or enhances the structural capacity of a member. surface preparation-steps taken after removal of deteriorated concrete, including conditioning ofthe surface of substrate at bond line and the cleaning of existing reinforcing steeL waterproofing-prevention of the passage of water, in liquid form, under hydrostatic pressure. 1.3-Repair methodology A basic understanding of the causes of concrete deficiencies is essential to perform meaningful evaluations and successful repairs. If the cause of a defici ency is understood, it is much more likely that an appropriate repair system will be selected and, consequently, that the repair will be successful and the maximum life of the repair will be obtained. Symptoms or observations of a deficiency should be differentiated from the actual cause of the deficiency, and it is imperative that causes and not symptoms be dealt with wherever possible or practical. For example, cracking can be a symptom of distress that may have a variety of causes such as drying shrinkage, thermal cycling, accidental loading, corrosion of embedded metal, or inadequate design or construction. Only after the cause or causes of deficiency are determined can rational decisions be made regarding the selection of a proper repair system and the implementation of the repair process (Fig. 1.1). 1.3.1 Condition evaluation-The first step in concrete repair is to evaluate the current condition of the concrete structure. This evaluation may include a review of available design and construction documents, structural analysis of the structure in its deteriorated condition, a review of available test data, a review of records of any previous repair work, review of maintenance records, a visual inspection of the structure, an evaluation of corrosion activity, destructive and nondestructive testing, and review oflaboratory results from chemical and petrographic analysis of concrete samples. Upon completion of this evaluation step, the personnel responsible for the evaluation should have a thorough standing of the condition of the concrete structure and be able to provide insights into the causes of the observed deterioration or distress. Additional information on conducting surveys can be found in ACI 20UR, 222R, 224.lR, 228.2R, 364.1R, and 437R. 1.3.2 Determination of causes of deterioration or distress-After the condition evaluation of a structure has been completed, !h: c.!u_se..ct __ ..i"... Page 2 of 8

668 Exhibit 22 ,. CONCRETE REPAIR MANUAL behavior to evaluate and design a structural repair, ening procedure, or both. Some design considerations follow and are discussed throughout this guide. 1.4.1 Current load distribution-In a deteriorated state, a structural member or system distributes dead and live loads differently than first assumed when the structure was new. Cracking, deteriorated concrete and corroded reinforcement alter the stiffness of members, which leads to changes in shear, moment, and axial load distribution.

As concrete and reinforcement are removed and replaced during the repair operation, these redistributed forces are further modified. To understand the final behavior of the structural system, the engineer should evaluate the redistribution of the forces. To fully re-establish the original load distribution, a member should be relieved of the load by jacking or other means. The repaired member and the repair itself supports the loads ently than would be assumed in the original or a new structure.

1.4.2 Compatibility

of materials-If a repair and the member have the same stiffness--for example, modulus of elasticity-the analysis of the repaired member may be the same as a new section. If the stiffness varies, however, then the composite nature of the repaired system should be considered. A mismatch of other material characteristics further exacerbates the effects of thermal changes, tions, and long-term creep and shrinkage effects. Different coefficients of thermal expansion of the repair and original material results in different dimensional changes. The engineer should design for the different movements, or the repair system should be similar to the thermal and dimensional characteristics of the original material. 1.4.3 Creep, shrinkage, or both-Reduction in length, area, or volume of both the repair and original materials due to creep, shrinkage, or both, affect the structures ability and durability. As an example, compared with the original material, high creep or shrinkage of repair materials results in loss of stiffness of the repair, redistributed forces, and increased deformations. The engineer should consider these effects in the design. 1.4.4 Vibration-When the installed repair material is in a plastic state or until adequate strength has been developed, vibration of a structure can result in reduced bonding of the repair material. Isolating the repairs or eliminating the vibration may be a design consideration.

1.4.5 Water

and vapor migration-Water or vapor migration through a concrete structure can degrade a repair. standing the cause ofthe migration and controlling it should be part of a repair design consideration. 1.4.6 Sqfety-The contractor is responsible for construction safety. Nevertheless, as the engineer considers a repair design, which may involve substantial concrete removal, steel reinforcing cutting, or both, he or she should notify the contractor of the need and extent of shoring and bracing. The local repair of one small section can affect a much larger area, of which the contractor may not be aware. 1.4.7 Material behavior characteristics-When new and innovative materials and systems are used for repair and strengthening, the structural behavior of the repaired section can differ substantially from the behavior of the original section. For example, if a beam's steel reinforcement corroded extensively and lost part of its capacity, the steel reinforcement may be replaced by fiber-reinforced polymer (CFRP) applied to the bottom face of the beam. The original yielding behavior ofsteel bar is replaced by FRP that is stronger, but has a elastic and brittle behavior. The behavior assumptions codes like ACI 318 are no longer valid. The engineer consider the behavior and performance of the new under the actual service and ultimate load, and design repair to provide at least an equivalent level of safety to original design. Such a design is outside the scope of ACI 1.5-Format and organization Chapter 2 discusses removal of deteriorated preparation of surfaces to receive repair materials, methods for concrete repair, and repair techniques reinforcing and prestressing steel. Chapter 3 various types of repair materials that may be used. reader is urged to use Chapters 2 and 3 in when selecting the repair material and method for a situation. Chapter 4 describes materials and systems may be used to protect repaired or unrepaired from deterioration. Chapter 5 provides methods strengthening an existing structure when repairing improving load-carrying capabilities, or both. Chapter provides references, including other appropriate documents and industry CHAPTER 2-CONCRETE PREPARA"rJON, AND REPAIR 2.1-lntroduction and general This chapter covers removal, excavation, or demolition of existing deteriorated concrete, preparation of the concrete surface to receive new material, preparation and repair of reinforcement, methods for anchoring repair materials to the existing concrete, and various methods that are available to place repair materials. The care that is exercised during the removal and preparation phases of a repair project can be the most important factor in determining the longevity of the repair, regardless of the material or technique used. Specific attention should be given to the removal of concrete around prestress strands, both bonded and unbonded, The high-energy-impact tools, such as chipping hammers, should avoid contact with the strand because this will reduce the strands' load-carrying capacity and may cause the wire(s) to rupture, which may lead to strand failure. . ..................*2.2--Concrete removal .. " i\" reprur project usually involves removal of damaged, or defective concrete. In most concrete repair projects, the zones of damaged concrete are not well defined. Most references state that all damaged or deteriorated material should be removed, but it is not always easy to determine when all such material has been removed or when too much good material has been removed. A common recommendation is to remove sound concrete for a defined distance beyond the delaminated area; thereby, exposing the reinforcing steel beyond the point of corroded steel. Page 3 of 8 CONCRETE REPAIR GUIDE Removal of concrete using explosives or other aggressive methods can damage the concrete that is intended to remain in place. For example, blasting with explosives or the use of some impact tools heavier than 12 kg (30 Ib) can result in additional delamination or cracking. Delaminated areas can be identified by using a hammer to take soundings. In most cases, such delaminations should be removed before repair materials are placed. :--itemovaT 'Of -concrete-using impact -tools -fiai 're'suTt-in: : small-scale microcracking damage (termed bruising) to the: _<?of_ layer is removed, a weakened plane may occur in the parent concrete below the repair material bond line. This condition can result in a low tensile rupture (bond) strength between the parent concrete and repair material. Thus, a perfectly sound and acceptable replacement material may fail due to improper surface preparation. All damaged or delaminated concrete, including bruising, at the interface ofthe repair and the parent concrete should be removed before placing the repair material. This may require one type of aggressive removal for gross removal followed by another type of removal for bruising.

-iii -aIr cases-in-wnicn concrete haS been rem ov"ea -from a"; : structure by primary means such as blasting or aggressive:

impact methods, the concrete left in place should be prepared:

by using a abrasive:

blasting, or:.

,!,;:t;r to remove any:

of the prepared surfaces should be conducted before placing repair materials.

Wetting the surface may help to identify the presence of cracking. Determination of the tensile strength (ACI 503R, Appendix A) by pull-off testing is advisable on prepared surfaces to determ ine the suitability of the surface to receive repair material. Removal of limited areas of concrete in a slab, wall, or column surface requires saw-cutting the perimeter of the removal area, providing an adequate minimum thickness of repair material at the edge of the repaired area, and mitigating the advancement of undetected incipient cracking. Feathering of repair materials generally should be avoided. The aration for shotcreting is an exception. ACI 506R mends tapered edges around the perimeter of such patches. Saw cutting can also improve the appearance ofthe repaired area. The general shape of the repaired areas should be as symmetrical as possible (ICRI 03730). Reentrant corners should be avoided. Large variations in the depth of removal in short distances should also be avoided. The texture ofthe prepared surface should be appropriate for the intended repair material (ICRI 03732). Every precaution should be made to avoid cutting lying reinforcement. Reviewing design drawings and using a covermeter or similar device provides data as to the location and depth of reinforcement. In addition, the removal of small areas of concrete is commonly used to confirm the location and depth of bars before saw cutting. Sections 2.2.1 through 2.2.18 present descriptions of many of the commonly used concrete removal techniques to help in the selection process. 2.2.1 General considerations-Concrete removal addresses deteriorated and damaged material. Some sound concrete, however, may be removed to permit structural modifications and to ensure that all unsound material is removed. The effectiveness of various removal techniques can differ for deteriorated and sound concrete. Some techniques may be more effective in sound concrete, while others may work better for deteriorated concrete. Concrete removal techniques selected should be effective, safe, economical, environmentally friendly, and minimize damage to the concrete left in place. The removal technique chosen may have a significant effect on the length of time that a structure will be out of service. Some techniques permit a significant portion of the work to be accomplished without removing the structure from service. The same removal technique, however, may not be suitable for all portions of a given structure. In some instances, a combination of removal techniques may be more appropriate to speed removal and limit damage to the remaining sound concrete. Trial field testing various removal techniques can help confirm the best procedures. In general, the engineer responsible for the design of the repair should specify the objectives to be achieved by the concrete removal, and the repair contractor should be allowed to select the most economical removal method, subject to the engineer's acceptance. In special stances, the engineer may also need to specify the removal techniques to be used and those that are prohibited. The mechanical properties of the concrete and the type and size of aggregate to be removed provide important information to determine the method and cost of concrete removal. The mechanical properties include compressive and tensile strengths. This information is also necessary for the engineer to specify the prepared surface condition and select the repair material, and it should be made available to contractors for bidding purposes.

2.2.2 Monitoring

and shoring during removal tions-It is essential to evaluate the removal operations to limit the extent of damage to the structure and to the concrete that remains. Structural elements may require shoring, removal of applied loads, or both, before concrete removal to prevent structural deformations, possible collapse, buckling, or slippage of reinforcement. Care should be used during removal of concrete to avoid cutting and damaging forcing steel. Because reinforcement is often misplaced, unanticipated damage may occur when saw cutting, impacting, or removing concrete. Careful monitoring is required throughout the concrete removal operation. This can be accomplished by visual inspection, sounding, use of a covermeter, or other means to locate reinforcement. The project specifications should assign responsibilities for the inspection ofthe prepared concrete. Sounding is an excellent means to detect delaminated concrete adjacent to the outermost layers of reinforcing steel. Subsurface cracks, the extent of deterioration, or other internal defects, however, may not be identified by this method alone. Other means of evaluation should be used to properly identify the extent of concrete to be removed. In Page 4 of 8 670 Exhibit 22 CONCRETE REPAIR MANUAL addition, sounding usually does not indicate near-surface microcracking or bruising. Only microscopic examination or bond testing may disclose near-surface damage. Subsurface evaluation (examination of the substrate) can provide valuable information about the condition of the concrete. This information may be obtained by the following methods before, during, or after concrete removal (ACI228.2R): a) Taking cores for visual examination, microscopic examination, compressive strength tests, and tensile strength tests; b) Pulse-velocity tests; c) Impact-echo tests; d) Bond tests (pull-off testing, ACI 503R Appendix A); e) Covermeter or similar equipment to locate ment and determine its depth below the surface; f) Infrared thermography; and g) Ground-penetrating radar (GPR). Many of these methods are discussed in ACI 228.2R. 2.2.3 Quantity of concrete to be removed-In most repair projects, all damaged or deteriorated concrete should be removed; however, the quantity of concrete to be removed is directly related to the elapsed time between preparation of the estimate and actual removal. Substantial overruns are common. Estimating inaccuracies can be minimized by a thorough condition survey as close as possible to the time the repair work is executed. Potential quantity overruns, based on field-measured quantities, should be taken into account. When, .by necessity, the condition survey is done far in advance of the repair work, the estimated quantities should be increased to account for continued deterioration. Because most concrete repair projects are based on unit prices, repair areas should be accurately measured before forms are installed. This is usually done jointly by the engineer and the contractor. It is not uncommon for estimated quantities to increase significantly between the detectable quantities and the actual quantity removed. ICRI 03735 provides guidelines for methods ofmeasurement for concrete repair work. 2.2.4 Classification of concrete removal Removal and excavation methods can be categorized by the way in which the process acts on the concrete. These categories are blasting, cutting, impacting, milling, hydrodemolition, presplitting, and abrading. Table

2.1 provides

a general description of these categories, lists the specific removal techniques within each category, and provides a summary of information on each technique. The techniques are discussed in detail in the following sections.

2.2.5 Blasting

methods-Blasting methods generally employ rapidly expanding gas confined within a series of bore holes to produce controlled fracture and removal of the concrete. The only blasting method addressed in this report is explosive blasting. Explosive blasting is the most cost-effective and expedient means for removing large quantities of concrete-for example, portions oflarge mass concrete foundations or walls. This method involves drilling bore holes, placing an explosive in each hole, and detonating the explosive. blasting techniques minimize damage to the material that remains after blasting. One such technique, cushion blasting, involves drilling a line of 75 mm (3 in.) diameter or smaller bore holes parallel to the removal face, loading each hole with light charges of explosive (usually detonating cord) distributed along its length, cushioning the charges by stemming each hole completely or in the collar with wet sand, and detonating the explosive with electric blasting caps. The uniform distribution and cushioning of the light charges produce a relatively sound surface with little overbreak. Blasting machines and electrical blasting-cap delay series are also used for controlled demolition and employ proper timing sequences to provide greater control in reducing ground vibration. Controlled blasting has been used fully on numerous repair projects. The selection of proper charge weight, borehole diameter, and borehole spacing for a repair project depends on the location of the structure, the acceptable degree of vibration and damage, and the quantity and quality of concrete to be removed. If at all possible, a pilot test program should be implemented to determine the optimum parameters. Because of the inherent dangers in the handling and usage of explosives, all phases of the blasting project should be performed by qualified, appropriately licensed personnel with proven experience and ability. 2.2.6 Cutting methods-Cutting methods generally employ mechanical sawing, intense heat, or high-pressure water jets to cut around the perimeter of concrete sections to permit their removal. The size ofthe sections that are cut free is governed by the available lifting and transporting equipment. The cutting methods include high-pressure water jets, saw cutting, diamond wire cutting, mechanical

.. JIle_f121!-l ____ ** _

_** a) High-pressure water jet (without abrasives)-A pressure water jet uses a small jet of water driven at high velocities, commonly producing pressures of 69 to 310 MPa (10,000 to 45,000 psi). A number of different types of water jets are currently being used. The most promising are the ultra high-pressure jet and the cavitating jet. Section 2.2.10 describes using a water jet as a primary removal method. Water jets used with abrasives are described in Section 2.2.11. : a b) sizes ranging from small (capable of being hand-held) to large (capable of cutting depths of up to 1.3 m [52 in.]). c) Diamond wire cutting-Diamond wire cutting is accomplished with a wire containing nodules impregnated with diamonds.

The wire is wrapped around the concrete mass to be cut and reconnected with the power pack to form a continuous loop. The loop is spun in the plane of the cut while being drawn through the concrete member. This system can be used to cut a structure of any size as long as the wire can be wrapped around the concrete. The limits of the power source determines the size of the concrete structure that can be cut. This system provides an efficient method for cutting up and dismantling large or small concrete structures. d) Mechanical shearing-The mechanical shearing method employs hydraulically powered jaws to cut concrete and reinforcing steel. This method is applicable for making cutouts through slabs, decks, and other thin concrete Page 5 of 8 CONCRETE REPAIR GUIDE Table 2.1-Summary of features and considerationsllimitations for concrete removal methods Category Features Conslderations/LimItations

2.2.5 Blasting

Uses rapidly expanding gas confined within a series of boreholes to produce controlled fracture and removal of conCTete. ............................ Explosives Most expedient method for removing large volumes where concrete section is 10 in. (250 mm) thick or more. Produces good fragmentation of concrete debris for easy removal" ............................ Requires highly skilled personnel for design and execution. Stringent safety regulations must be complied with regarding the transportation, storage, and use of explosives due to their inherent dangers. Blast energy must be controlled to avoid damage to surrounding improvements resulting from air blast OPIleIl6_ lIf_dovibNticot,..uodoll,..lIbRso

- - - - 2.2.6Cutling Uses perimeter culs to remove large pieces of concrete.

High-pressure waler jet (without abrasives) Applicable for making cutouts through slabs, decks, and other thin concrete members. Cuts irregular and curved shapes. Makes cutouts without overcutting corners. Cut. flush with intersecting surface *. io Handling of debris is efficient because bulk of concrete is removed in large pieces. Cutouts for removal limited to thin sections. Cutting is typically slower and more costly than diamond blade sawing. Moderate levels of noise may be produced. Controlling flow of waste water may be required. Additional safety precautions are required due to the high water pressure produced by the system. 1*1*t

..........................

_*** Applicable for making cutouts through slabs, decks, and other thin concrete members. Makes precision cuts. No dust or vibration is produced. Handling of debris is efficient because bulk of concrete is removed in large pieces. ..**...*...*....*....**..**. Cutouts for removal limited to thin sections. Performance is affected by type of diamonds and the mond-to-metal bond in blade segments (segment lion is based on aggregate hardness). The higber the percentage of steel reioforcement in cuts, the slower and more costly the cutting. The harder the aggregate, the slower and more costly the cutting. Controlling flow of waste water may be required.

2.2.6 Cullmg

(continued) culling Applicable for cutting large and/or thick pieces of concrete. The diamond wire chain can be infinitely long. No dust or vibration is produced. Large blocks of concrete can be easily lifted out by a crane or other mechanical methods. The cutting operation can be equally efficient in any direction. The cutting cbain must be coatinuous. Access to drill holes through the concrete must be available. Water must be available to the chain. Controlling the flow of waste water may be required. The harder the aggregate andlor concrete, the slower and more costly the cutting. Performance is affected by the quality, type, and number of diamonds as well as the diamond-to-metal bond in the chain. 2.2.6 Culling (contmued) Mechanical s/!earing Applicable for making cutouts through slabs, decks, and other thin concrete members. Steel reinforcement can be cut Limited noise and vibration are produced. Handling of debris is efficient because bulk of concrete is removed in large pieces. Limited to thin sections where an edge is available or a hole can be made to start the cuI. Exposed reinforcing steel is damaged beyond reuse. Remaining concrete is damaged. Extremely rugged profile is produced at the cut edge. Ragged feather edges remain after removal. 2.2.6 CUlling (contmued) i Slileh drilling Applicable for making cutouts through concrete members where access to only one face is feasible. Handling of debris is mQre efficient because bulk of concrete is removed in large pieces. Rotary-percussion drilling is significantly more expedient and economical than diamond COre drilling; however, it results in more damage to the concrete that remains, especially at the point of exit from the concrete. Depth of cuts is dependent on accuracy of drilling ment in maintaining overlap between boles with depth and diameter of the boreholes drilled. The deeper the cut, the greater borehole diameter required to maintain lap between adjacent holes and the greater the cost. Uncut portions between adjacent boreholes will hamper or prevent the removaL Cutting reinforced concrete increases the cutting rime and increases the cost Aggregate tougbness for percussion drilling and aggregate harduess for diamond coring will affect cutting cost and rate. Personnel must wear hearing protection due to high noise levels. members. It is especially applicable where total demolition of the member is desired. The major limitation of this method is that cuts should be started from free edges or from holes made by hand-held breakers or other means. e) Stitch drilling-The stitch-drilling method employs the use of overlapping boreholes along the removal perimeter to cut out sections for removal. This method is applicable for making cutouts through concrete members where access to only one face is possible, and the depth of cut is greater than can be economically cut by the diamond-blade method. The primary drawback of stitch drilling is the potential for costly removal complications if the cutting depth exceeds the accumcy of the drilling equipment, so that uncut concrete remains between adjacent holes. t) Thermal cutting-This method requires powder torch, thermal lance, and powder lance, which develop intense heat generated by the reaction between oxygen and powdered metals to melt a slot into concrete. The thermal device's ability for removing concrete from structures mainly depends on the mte at which the resulting slag can flow from the slot. These devices use intense heat and are especially effective for cutting reinforced concrete; however, they are considered slow, relatively expensive, and are not widely used. Page 6 of 8 672 Exhibit 22 CONCRETE REPAIR Table 2.1 (cont.)-Summary of features and considerationsllimitations for concrete removal Category Features Lons.aeratlOns/Llmltations 4.t.CJ (;utling (contmued) Jl!e,mal culling Applicable for making cutouts through heavily reinforced Limited availability commercially. decks, beams, walls, and other thin to medium concrere Not applicable for cuts where slag flow is restricted. members. Remaining concrere has thenna! damage with more extensive An effective means of cutting reinforced concrete. damage occurring around steel reinforcement. Cuts irregular shapes. Produces smoke and fumes. Produces minimal noise, vibrations, and dust. Personnel must be protected from heat and hot slag produced by cutting operation. z.z.7 Impacting Hand-hela breakers Uses repeated striking of the surfuce with a mass to fracture Applicable for limited volumes of concrete removal. Performance is a function of concrete soundness and and spall the concrete. aggregate toughness. Widely available commercially. Applicable where blow energy must be limited. Significant loss of productivity occurs when breaking action is other than downward. Can be used in areas of limited work space. Removal boundaries will likely require saw cutting to Produces relatively small and easily handled debris. avoid feathered Concrete that remains may be damaged Produces high levels of noise, dust, and Boom-mounted breakers Applicable for full.depth removal from slabs, decks, and Blow energy delivered to the concrete may have to be other thin concrete members and for surface removal limited to protect the structure being repaired and the from more massive concrete structures. surrounding structures from damage due to high cyclic Can be used for vertical and overhead surfaces. energy generated. Widely available commercially. Performance is a function of concrete soundness and aggregate toughness. ! Produces easily handled debris. Damages remaining Damages reinforcing Produces feathered Produces high level of noise and 2.2.7 Impacting (contmued) I Scabblers Low initial cost. High cyclic energy applied to a structure will produce Can be operated by unskilled labor. fractures in the remaining concrete surface area. Can be used in areas oflimited work space. Produces high level of noise and dust. Removes dereriorated concrete from wall or floor surfaces Limited depth removal. efficiently. Readily available commercially.

2.2.8 Milling

Scarifier Uses scarifiers to remove concrete surfaces. Removal is limited to concrete without steel reinforcement. from slabs, decks, and mass concrete. Applicable for removing deteriorated concrere surfaces Sound concrete significantly reduces the rate of removal. Boom-mounted cutters are applicable for removal from Can damage concrete that remains (microcracking). wall and ceiling surfaces. Noise, vibration, and dust are produced. Removal profile can be controlled . .......**....................Mi;tll<lfl JllWC4I..

.*....*.......*...........**

2.Z.9 HytJrodemolilion Applicable for removal of detenorated concrete from Productivity IS .=uced when sound concrete IS Uses high-pressure water to remove concrete. surfaces of bridges and parking decks and other deteriorated being removed. surfaces where removal depth is 6 in (150 mm) or less. Removal profile will vary with changes in depth of deterioration. .. Steel reinforcing is left clean and undamaged for reuse. Method requires large source of potable water to meet : Method produces easily bandied, aggregate-sized debris. water Waste water may bave to be An environmental impact statement may be required ls

Personnel must wear hearing prole<:tion due to the high *

..** Flying debris is produced.

Additional safety requirements are required due to the high pressures produced by these systems.I M *************************************************************************************

1 2.2.7 Impacting methods-Impacting methods are the most commonly used concrete removal systems. They repeatedly strike a concrete surface with a high-energy tool or a large mass to fracture and spall the concrete. The use of these methods in partial-depth concrete removal can result in microcracking on the surface of the concrete left in place. Extensive microcracking results in a weakened plane below the bond line. Currently, the committee is unable to provide definitive guidelines to prevent such damage when using impact methods; however, factors such as the weight and size of the equipment should be considered to minimize microcracking. Detennination of the tensile strength by off testing is recommended to detennine the suitability of the surface to receive repair materials. Additionally, after impacting secondary methods, such as sandblasting, sive blasting, and water blasting, may be required to remove excessive micro cracking. a) Hand-held breakers-The hand-held breaker or chipping hammer is probably the best known of all concrete removal devices. Hand-held breakers are available in various sizes with different levels of energy and efficiency. These tools are generally defined by weight and vary in size from 3.5 to 41 kg (8 to 90 lb). (Note: the larger the hammer, such as 14 kg [30 lb] and larger, the greater the potential for racking.) The smaller hand-held breakers, such as 7 kg (15Ib) and smaller, are used in partial removal of unsound concrete or concrete around reinforcing steel because they do little damage to surrounding concrete. Larger breakers are used for complete removal oflarge volumes of concrete or inations. Care should be exercised when selecting the size of ____ .... __ .J'""" Page 7 of 8 ---Exhibit 22 CONCRETE REPAIR MANUAL (0.1 to 4 in.). Milling operations usually leave a surface with less micro fractures than impact (Virginia Transportation Research Council 2.2.9 scarifier is a concrete cutting tool that employs the rotary action and mass of its cutter bits to rout cuts into concrete surfaces. It removes loose concrete fragments (scale) from freshly blasted surfaces and removes concrete that is cracked and weakened by an expansive agent. It also is the sole method of removing deteriorated and sound concrete in which some ofthe concrete contains form ties and wire mesh. Scarifiers are available in a range of sizes. The scarifier is an effective tool for removing deteriorated concrete on vertical and horizontal surfaces. Other advantages include well-defined limits of concrete removal, relatively small and easily handled concrete debris, and simplicity of operation. ; * -:f.U Ii* '1Iyaroc!emoliiion"::: rftgh:pressure

water -Jetting-: (hydrodemolition) can be used to remove concrete to : : preserve and clean the steel reinforcement for reuse and to : .-.. ihitiimize-microcrac'kinifo-tne remainiiis iri..praM' cOn*crete.* --h'a";.a 'hl g 1; disintegrates concrete, returning it to sand and pieces. This process works on sound or deteriorated and leaves a rough profile. Hydrodemolition punches the full depth of slabs in small areas when the concrete unsound or when full-depth patches are inadequately r!' to* the*Side' wans.*fIyaroaemolitioit S'liourd" not6e' useit in* structures with unbonded tendons, except under the direct .of 2-

.***************** High-pressure water jets in the 70 MPa (10,000 psi) range require 130 to 150 Llmin (35 to 40 gal.lmin). As the pressure increases to 100 to 140 MPa (15,000 to 20,000 psi), the water demand varies from 75 to 150 Llmin (20 to 40 gal.lmin) (Nittenger 1997). The equipment manufacturer should be consulted to confirm the water demand. Ultra-high-pressure equipment operating at 170 to 240 MPa (25,000 to 35,000 psi) has the capability of milling concrete to depths on to 150 mm (0.1 to 6 in.). Containment and subsequent disposal of the water are requirements of the hydrodemolition process. Many localities require this water to be filtered and then treated to reduce the alkalinity and particulates before the water can be released into a storm or wastewater sy stem. Water jet lances operating at pressures of 70 to 140 MPa (10,000 to 20,000 psi) and having a water demand of75 to 150 Llmin (20 to 40 gal./min) are available. They are capable of cutting sections of concrete or selectively removing : surface concrete in areas that are difficult to reach with larger * .......................2.2.11 Presplitting methods-Presplitting methods use hydraulic splitters, water pressure pulses, or expansive icals used in boreholes drilled at points along a predetermined line to induce a crack plane for the removal of concrete. The pattern, spacing, and depth of the boreholes affect the direction and extent of the crack planes that propagate. Presplitting is generally used in mass concrete structures or unreinforced concrete. a) Hydraulic splitter-The hydraulic splitter is a wedging device that is used in predrilled boreholes to split concrete into sections. This method has potential as a primary means for removal oflarge volumes of material from mass concrete structures. Secondary means of separating and handling the concrete, however, may be required where reinforcing steel is involved. b) Water-pulse splitter-The water-pressure pulse method requires that the boreholes be filled with water. A device, or devices, containing a very small explosive charge is placed into one or more holes, and the explosive is detonated. The explosion creates a high-pressure pulse that is transmitted through the water to the structure, cracking the concrete. Secondary means may be required to complete the removal of reinforced concrete. This method does not work if the concrete is so badly cracked or deteriorated that it does not hold water in the drill holes. c) Expansive product agents-Commercially available cementitious expansive product agents, such as those containing aluminum powder, when correctly mixed with water, exhibit a large increase in volume over a short period of time. By placing the expansive agent in boreholes located in a predetermined pattern within a concrete structure, the concrete can be split in a controlled manner for removal. This technique has potential as a primary means ofremoving large volumes of material from concrete structures and is best suited for use in holes of significant depth. Secondary means may be required to complete the separation and removal of concrete from the reinforcement. A key advantage to the use of expansive agents is the relatively nonviolent nature of the process and the reduced tendency to disturb the adjacent concrete. 2.2.12 Abrading blasting-Abrading blasting removes concrete by propelling an abrasive medium at high velocity against the concrete surface to abrade it. Abrasive blasting is typically used to remove surface contaminants and as a final surface preparation. Commonly used methods include blasting, shotblasting, and high-pressure water blasting. 2.2.13 Sandblasting-Sandblasting is the most commonly used method of cleaning concrete and reinforcing steel in the construction industry. The process uses common sands, silica sands, or metallic sands as the primary abrading tool. The process may be executed in one ofthree methods. 2.2.14 Dry sandblasting-Sands are projected at the concrete or steel in a stream of high-pressure air in the open atmosphere. The sand particles are usually angular and may range in size from passing a 212 to a 4.75 mm (No. 70 to a No.4) sieve. The rougher the required surface condition, the larger the sand particle size . The sand particles are propelled at the surface in a stream of compressed air at a minimum pressure of86O kPa (I 25 psi). The compressor size varies, depending on the size of the blasting pot. Finer sands are used for removing contaminants and laitance from the concrete and loose scale from forcing steel. Coarser sands are commonly used to expose fine and coarse aggregates in the concrete by removing the paste or tightly bonded corrosion products from reinforcing steel. Although sandblasting has the ability to cut quite deeply into concrete, it is not economically practical to remove more than 6 mm (0.25 in.) from the concrete surface. -----------Page 8 of S Exhibit 23: Hydrodemolotion of Concrete Surfaces and Reinforced Concrete © 2012. Performance Improvement International-Appendix Exhibit 23 Hydrodemolition of Concrete Surfaces and Reinforced Andreas Fundamentals of Hydrodemolition

2.1 Properties

and structure of high-speed water 2.1.1 Kinematics of high-speed water 2.1.2 Structure of high-speed water 2.1.3 Water drop

2.2 Material

loading due to stationary 2.2.1 Generalloading 2.2.2 Material

2.2.3 Material

resistance

2.3 Process

parameter effects on material 2.3.1 Parameter 2.3.2 Pump pressure 2.3.3 Nozzle diameter 2.3.4 Stand-off distance 2.3.5 Traverse rate 2.3.6 Traverse increment 2.3.7 Impact angle 2.3.8 Nozzle movement 2.4 Concrete parameter effects on material 2.4.1 Material failure 2.4.2 Compressive strength 2.4.3 Aggregate fineness 2.4.4 Aggregate sort 2.4.5 Porosity 2.4.6 Steel bar reinforcement 2.4.7 Steel fibre reinforcement 2.5 Hydrodemolition copyrighted material, do not reproduce or distribute Page 1 of 21

23 Fundamentals of Hydrodemolition 33 orifice type 1 A 0.8 :J f ::l f c. D.B c: 0 orifice type 2 11 c: CI III i In 0.4 -0.2 A G> > i & 0 0 200 400 BOO 800 Relative jet length Figure 2.8 Orifice type effects on stagnation pressure profiles (Leach and Walker. 1 966) Ps(x) (2.23)(:;f'Ps(O) for x<3'xc= K*=0.2 7 +0.07 5 '(x/xe f . for x>3'x c: K*=0.3. The loading duration is given through the exposure time which is for a moving jet: (2.24) The difference between the stagnation pressure at the surface and the pressure inside the target material forces a certain volume of water to penetrate the structure. This volume is (2.25) where 00*=0 is the limiting case for a completely non-permeable material, and 00*= 1 is the limiting case when the whole volume delivered by the nozzle penetrates into the material. For 00*>0, the following three cases can be distinguished: Page 2 of 21 Exhibit 23 34 Hydrodemolition of concrete surfaces and reinforced concrete structures (i) the water flows into a crack and creates a corresponding stress at the crack tip; (ii) the water flows into a capillary which results in pressure amplification; (iii) the water flows through an open pore system and creates friction forces to the structural elements (e.g. grains) . .. ..CCLSc.Jt).,was experimentally investigated by Mazurkiewicz et al. (1986) whose results are illustrated in Fig. 2.9. Although the experiments were restricted to comparatively low water pressures, a linear relationship between pump pressure and pressure developed at the crack tip could be noted. If jet velocity is considered instead of pump pressure, the following relationship is valid: (2.26) 10 8 l: Q... c 6 ... o 10 4 :1 III Ps III 2 y. o o 8 16 24 32 stagnation pressure in MPa Figure 2.9 Water flow into a crack (Mazurkiewicz et aI.. 1986) The constant was found to be C 1=0.22 which corresponded closely to values estimated by Momber and Kovacevic (1995) who found 0.19<C}<0.21 based on an LEFM-model. Lin et al. (1996) used a finite element code to investigate the influence of the water jet velocity on principal stresses as well as stress intensity at the crack tip. Some of their results are shown in Fig. 2.10. The calculated points (filled circles) can be approximated by a square-root relationships which verifies Eq. (2.25). The open circles in Fig. 2.10 are experimental points estimated by Witzel (1998) on rocks. However, the calculated points in Fig. 2.10 can be approximated by an almost linear function in the range of low jet velocities up to 300 m/s. A Page 3 of 21 Exhibit 23 Fundamentals of Hydrodemolition 35 150 r-------------------;r---, era':. l ength 0,2 nH" /1 nmberolcracks 3 mater 31 t,asali I £ 120 // E E 40 r-;1 KIa:: '/ I / 0 pOint for / /y' /0 JurassIC ilme.itone gnnltt: concrete 855 ,;:oncr e-te 9,.. r o r es ult Witzel f 1938.1 B45 ..o 200 40r] 1300 800 Jet velocity <n ml': Figure 2.10 Relationship between jet velocity and stress intensity (Lin et al.. 1996) mercury intrusion study performed by Momber (1992) on cementitious composites showed clearly that the fracture started in the interfacial zone between cement matrix and aggregate which is known to be the weakest link in conventional concrete. Moreover, fracture propagation was mainly affected by aggregate size and bution. A detailed microscopic study on crack-aggregate interactions in concrete samples eroded by water jets were made by Momber (2003b) who found clear evidence of crack del1ection, crack stopping, crack tip bluntness, but also of crack bridging and crack face friction. Some of these features are illustrated in Fig. 2.11. Case (ii) corresponds to capillary-like micropores. A model for pressure intensification in "blind", air filled tubes was developed by Evers et al. (1982). A Figure 2.11 Microscopic features of concrete eroded by high-speed water jets (Mombo; 2003b) Page 4 of 21 E x h i b it 23 36 Hydrodemolition of concrete surfaces and reinforced concrete structures III o ::l. 20 :5 1 t traverse rate: .. ----.. x traverse rate: J.O m i s W rx d p L p gas , /.. ... pump pressure: 13.8 MPa o (I 200 400 600 800 l,OOO Pore slenderness Lp f dp Figure 2.12 Pressure amplification in a pore subjected by a water jet (Evers et aI., 1982) liquid jet, that strikes a pore opening, transports liquid into this capillary and displaces the air. A force balance as shown in Fig. 2.12 delivers the following: P 'A ='1' 'Pf"X+P *A (2.27)1 C S 2 C Thus, pressure intensification depends on shear stress, pore geometry and perimeter of the liquid column. The approach was later modified by Evers and E ddingfield (1984) by considering compressibility effects. T he capillary model was verified experimentally for rather large pores and low pressures. For a pore with a diameter of 0.2 mm and a length of 38 mm where a water jet with a velocity of 71 mls traversed over with a speed of 6.0 mls (corresponding exposure time would be 3.3,10-5 s), a pressure intensification of 3.5 was estimated. Case (iii) was in detail investigated by Rehbinder (1977) for porous solids. Based on a known pressure gradient, the speed, the liquid penetrates the pore system at, can be estimated with Darcy's Law: k p = --'gradps v f (2.28)[lw The frictional force acting on an individual grain due to the liquid flow can be approximated for low Reynolds numbers and spherical particles as follows: Page 5 o f 21 Exhibit 23 Fundamentals oj Hydrodemolition 37 Further treatment -especially the replacement of the constant C -delivers the following relationship (Rehbinder. 1977): If this frictional force exceeds the cohesion force to neighbouring grains. the grain in question will be removed. 2.2.2 Material response Important information about the response of concrete to water jet loading is stored in the structure of fracture faces. Depending on loading regime and material structure. two general types of macroscopic failure can be distinguished:

type I: sections without brittle fracture features;
type II: sections with dominant brittle fracture features.

Both types. that were probably first distinguished by Nikonov (1971) for coal cutting with water jets. are illustrated in Fig. 2.13. It can be noted that type-II failure occurred always near larger aggregate particles. Investigations on rock materials have shown that the transition from type-I to type-II failure depended on jet velOCity and exposure time. The transition jet velocity was a function of the Figure 2.13 Failure types in concrete during hydrodemolition (Momber; 2004a) Page 6 of 2l Exhibit 23 38 Hydrodemolition of concrete surfaces and reinforced concrete structures , 11\, I : ,I \ I/ :\ , microscop,r e ffe -statl stl c 3 1 r a n g e I :1 \\ .. \ / i4 .I \. , ma Nocopl c -\" I\' , i effe cts , ' .../ i' o 100 200 300 Je t lIeloeity in m .l s Figure 2.14 Effect of jet velocity on kerf width variation in concrete (Momber and Kovacevic, 1995) Figure 2.15 Fracture surface of a cement sample cut with a high-speed water jet (Momber and Kovacevic, 1994) Pa ge 7 of 21 Exhibit 23 Fundamentals of Hydrodemolition 39 tensile strength, whereas the transition exposure time followed a more complex relationship (Sugawara et at, 1998). Momber and Kovacevic (1995) have investigated the influence of jet velocity on the fracture statistics of concrete surfaces. The results illustrated in Fig. 2.14 show that the standard deviation of the kerf width started to drop at a certain jet velocity (at about 300 m/s). If this velocity was exceeded the failure process was more homogeneous. Effects due to the microstructure (e.g. microcrack distribution) were eliminated, and a macroscopic material property, lets say tensile strength, determined the material response. The average kerf width was always larger for a plain matrix material (cement matrix) than for a composite (mortar or concrete) due to the rather unrestrained fracture propagation in the matrix. This is illustrated in Fig. 2.15 showing the very smooth fracture face in a cement matrix. It may, however, be noted that the roughness of the surface increased as the fracture propagated (from top to bottom). Such effects are known from other brittle material as well (Hull. 1999: Schonert, 1972) and is considered to be a result of crack acceleration. If two concrete materials were compared, a water jet formed wider kerfs in the material with the coarser aggregates (Momber. 1998b; Werner, 1991a). 2.2.1 Maurial resistance parameurs Conventional properties of concrete, namely strength parameters, can not characterise the reSistance against water jet erosion. This was found in very detailed studies performed by Kauw (1996) and Werner (1991a); an illustrative example is shown in Fig. 2.16. Figure 2.17 shows the situation if the compressive strength in Fig. 2.16 is replaced by the characteristic length. The characteristic length is a fracture parameter originating from a fracture model introduced for concrete by Hillerborg et al. (1976); see Section 1.4.2. The relationship between volumetric erosion rate and characteristic length is: (2.31) whereby the very right term expresses an empirical relationship between aggregate size, compressive strength, and characteristic length (Hilsdorf and Brameshuber, 1991). It was shown that Eq. (2.31) also holds for other impact situations, namely for the comminution of concrete in a jaw breaker (Momber, 2002b). The sup* porting effect of coarse aggregates on concrete hydrodemolition. as expressed in Eq. (2.31). was verified by Werner (1991a). The proportionality coefficient is considered to be a machine parameter. Rehbinder (1978) defined a so.called 'specific erodability' to evaluate the resistance of porous solids against water jet erosion. This parameter is defined as follows: _ k p R(2.32) Page 8 of 21

Exhibit 23 40 Hydrotiemoittion of concrete surfaces and reinforced concrete structures 1.2 * + * * + *1 O.S l-* * *..

E +. *
i :II ** ** * * * .! *! 0.4 i
o o 20 60 Compressive strength in MPa Figure 2.16 Relationship between removal rate in concrete and compressive strength (Werner; 1991) 1.2 ,..-------------------, r I O.S J i J i 0.4 Max. aggregate size in mm: ... 16
a .. 4 o o 500 1.000 1.eoo Charaderistic Length in mm Figure 2.17 Relationship between removal rate in concrete and characteristic length (MDmber; 200 3c); values correspond to 1.-'ig. 2.16 Page 9 of 21 Exhibit 23 Fundamentals of Hydrodemolition 41 The higher specific erodability.

the lower the resistance. The physical unit of this parameter is [m 3/N*s]. The right term of Eq. (2.32) allows the experimental estimation of R E* whereby AhMI Ap is simply the progress of an erosion pressure function. Specific erodability increases as grain size or viscosity decreases, and as permeability increases. It was in fact shown by Kolle and Marvin (2000) that the resistance of rock materials was higher for water as a liquid compared to liquefied carbon dioxide (having a lower viscosity). If, however, viscosity is a constant value, erosion resistance depend only on pore structure (Rehbinder, 1980): (2.33) Thus, resistance is proportional to pore slenderness and it decreases if -for a given pore slenderness -grain size decreases. These results are partly in agreement with experimental results obtained by Evers et a1. (1982) on rocks. 2.3 Process parameter effects on material removal 2.3.1 Parameter defJnitions Basic target parameters include thickness of removed layers (h M), volume removal (V M), volumetric removal rate eVM), and removal width (w M). They are illustrated in Fig. 2.18. For the erosion with a stationary water jet, these parameters are related through the following approximation: (2.34) For a given removal width, a certain concrete volume must be removed to completely erode a layer of given thickness. A maximum volume removal is desired. The energy efficiency of the demolition process is given by the specific energy: (2.35) This parameter should be as low as possible; its physical unit is [kJ/m 3]. The volumetric removal rate is the mass removed in a given period of time: Page 10 of 21 Exhibit 23 42 Hydrodemolition of concrete surfaces and reinforced concrete structures p nozzle carrier / Figure 2.18 Target and process parameters for hydrodemolition Volumetric removal rate should also be maximum; its physical unit is [m 3/h]. Other target parameters that may focus on the surface quality, such as roughness or cleanliness, are not considered in this paragraph. Hydrodemolition process parameters are summarised in Fig. 2.18. They can be subdivided into hydraulic parameters and performance parameters. Hydraulic parameters characterise the pump-nozzle-system; they include the following:

operating pressure (p);
volumetric flow rate (QA);
nozzle diameter (d N). Typical relationships between these parameters are described in Chapter 3. Performance parameters are more related to the process and include the following:
stand-off distance (x);
traverse rate (v T);
traverse increment (y);
impact angle (<1>>;
nozzle guidance.

The traverse rate covers additional parameters, such as the number of cleaning steps, n s' and the exposure time tEo _________________ I. --------------

". Page 11 of ". 21 Exhibit 23 56 Hydrodemolition of concrete surfaces and reinforced concrete structures

2.4 Concrete

parameter effects on material removal 2.4.1 Material failure types Compressive strength is the standard strength parameter of concrete that can be evaluated under site conditions as well. The most common method is to use cylinder cores drilled off the structure. Momber (1998b) was probably the flIst to suggest to use the way how a cylinder fails during the compression test as a criterion of the material behaviour during hydrodemolition. The studies showed that two general types of failure. type I and type II as listed in Table 2.5. can be distinguished during the compression testing (see Momber (2000f) for more infonnation about the testing of testing of concrete cores). If the failure type I is observed. the following features can be expected for the hydrodemolition process (compare Fig. 2.30a): the predominant material removal mode is intergranular erosion of the cement matrix; the aggregates are completely exposed; the eroded surface is cleaved and uneven; a comparatively large number of small. regular debris is generated; the generated kerfs are deep but small; Table 2.5 Failure types during cylinder core compreSsion testing of concrete (Momber. 1998b. 20001) Feature Type II Failure mode Slow crumbling Rapid crushing Primary debris Two; symmetric More than two: asymmetric Secondary debris Many small debris: round Several larger debriS: irregular Debris surface Aggregates exposed. undamaged Aggregates fractured If the failure type II is observed. the following features can be expected for the hydrodemolition process (compare Fig. 2.30b): the predominant material removal mode is transgranular spalling of the concrete structure; the eroded surface is even; just a few gaps appear; the eroded surface preferably contains broken aggregate grains; a comparatively low number of large. irregular debris is generated; the generated kerfs are shallow but wide. Type II-response could be observed usually with concrete mixtures containing large. irregular (broken) aggregate. It is assumed that the transition criterion, derived in Section 7.1.2 is partly responsible for this behaviour. Rather hard materials, such as many aggregates, respond elastic. whereas softer materials. such as cement matrix. show plastic response (see Table 1.3 for typical hardness values). Page 12 of 21 Exhibit 23 Fundamentals of Hydrodemolition 57 2.4.2 Compressive strength effects The influence of the compressive strength on the relative erosion rate is already illustrated in Fig. 2.16. There is no general trend between both parameters and it seems that standard compressive strength is not a useful parameter to evaluate concrete resistance. An equal trend was reported by Kauw (1996). However. the figure changes if maximum aggregate diameter is considered as done in the graph in Fig. 2.35. Under this circumstances compressive strength can characterise the efficiency of hydrodemolition processes. For large aggregate diameters (16 mm) removal rate increases if compressive strength increases, whereas the opposite trend can be observed for small aggregate diameters (4 mm). For a given compressive strength, removal rate is always higher for a concrete made with coarse aggregates. The reasons for this behaviour are already outlined in Section 2.2.2. A strong and coarse concrete enables the formation of rather large radial fractures in the structure. Based on fracture mechanics arguments. Momber (2003b) introduced the following semi-empirical relationship: Note the agreement with the trends in Fig. 2.35 at least for the medium-grained and fine-grained concrete mixtures. iii :> 0 E 4>.... 4> E :l (5 :> <II> :> <II> (I F .... ...... --....." .. AlBS

B/CS 1 "1 ex: Compressive strength in MPa Figure 2.35 Effects of compressive strength and aggregate size on removal rate (Werner. 1991 a) Page 13 of 21

Exhibit 23 58 Hydrodemolilion of con c r e t e surfaces and reinforced concrete structures

2.4.3 Aggregate

fineness effects Aspects of aggregate fineness are already illustrated in Fig. 2.35 showing that concrete mixtures with fine aggregates are more resistant against water jet erosion. A design parameter that characterises aggregate fineness is the k-number (graining number). The larger the k-number the higher the amount of coarse particles. In Fig. 2.36, the relative removal rate is plotted against the k-numbers for certain sieve lines. A linear relationship, that proves the results obtained in Section 2.4.2, can be noted between both parameters. The coarser the mixture the higher the demolition efficiency. Another design parameter for concrete manufacture is the flour particle content which is the sum of cement and very fine aggregate particles. It was proven by Werner (1991a) that this parameter did not affect removal rate notably. 3 1.2 ...-------------------, -tI:I... 'i > CI E 0.8 -.... I,)';: CIl E 0.-aggregate: rhine gravel aggregate size: 0-8 mm o 2.25 2.5 2.75 3.25 k-number Figure 2.36 Effect of aggregate finen e ss on removal rate (Werner. 1991a) 2.4.4 Aggregate sort effects Two basic types of aggregates can be distinguished in concrete. The first type is fine aggregate which is often referred to as 'sand' only. In fact. fine aggregate consists usually of rounded river (quartz) sand. The second type is coarse aggregate which is often referred to as 'gravel'. Coarse aggregate material include in fact gravel (rounded river gravel), but also broken rocks, namely basalt or limestone. It is known that the sort of coarse aggregate affects the response of concrete to hydrodemolition. This includes not only the resistance of the material but also its fail ure behaviour. Figure 2.37 shows the effects of coarse aggregate sort and sieve Page 14 of 2 1 Exhibit 23 Fundamentals of Hydrodemolition 59 line on the relative removal rate. Notably effects can be noted. The difference between maximum and minimum removal rate is about 470%. Removal rate is maximum for a limestone-based concrete under aU circumstances, followed by the gravel-based concrete. The basalt-based concrete has the highest hydrodemolition resistance. It also seems that the effects of aggregate sort become more important for the coarser mixtures. The corresponding eroded surfaces are rather even and characterised by always broken aggregates in case of limestone, whereas they are very uneven and characterised by mainly (but not exclUSively) broken aggregates in case of basalt. In case of river gravel the amount of broken aggregate was less than 30% (Werner. 1991a). Numerous aspects cause the different behaviours of the materials, among them morphology and surface energy of the aggregates and the compositions and properties of the aggregate-matrix interfaces. 1.5 1.2 "; :> c E Q.I .... 0 .9 <Q 0.8 E CIl... U.;: Gi Q dmm CIl > Qj a: 40 50 60 Cement matrix porosity in vol.-% Figure 2.38 Effect of cement paste porosity on removal rate (Werner, 1991a) 2.4.6 Steel bar reinforcement effects Many practical hydrodemolition applications include reinforced concrete structures. Effects of steel bar reinforcement on volumetric removal rate are shown in Fig. 2.39a where the influence of the depth of reinforcement is illustrated as well. A distinct drop in efficiency can be noted if the depth of reinforcement exceeds a value of 100 mm. which applies to a plain non-reinforced concrete. Thus. reinforcement supports the removal process. The thickness of the concrete layer that covers the reinforcement does. however. not play any role. The same relationship is valid for the removal depth (Kauw. 1996). The reason for the increase in hydrodemolition efficiency due to reinforcement is the installation of weak zones in the interface between concrete and reinforcement bars (Balaguru and Shah, 1992). If a single steel bar is replaced by a bar bundle, as shown in Fig. 2.39b, removal rate drops slightly. However, if a dense reinforcement bar net exists, the concrete removal process is disturbed and 'shadows zones' form at the lower surface of the steel bars. A typical practical example is shown in Fig. 2.40. These 'shadow zones' can be avoided by using complex nozzle guiding systems that include angled jets. The effect of reinforcement becomes stronger if the structure is damaged through chlorides. In that case rust grows at the corroded steel and the stresses generated due to volume expansion form cracks in the surrounding concrete. These cracks are exploited by the water jet. An increase in efficiency of about 15% was estimated if chloride-corroded reinforced concrete was treated instead of non-corroded reinforced concrete (Kauw, 1996). Page 16 of 21 Exh i b i t 23 Fundamentals of Hydrodemolition 61 a 4.8 .. ... .E II u.. ii 0 E u S II E '0 > corresponds to unrelnforced concrete 3.6 b 6 5 .E ! 4 j 0 E 0; 2 c; :> 0 0 40 80 120 bar bar bundle Depth of reinforcement In mm Degree of relnforcemettt Figure 2.39 Effect of steel bar reinforcement on removal rate (Kauw. 1996) a-single reinforcement bar b-bar bundle Figure 2.40 Shadow zones. formed under reinforcement bars during hydrodemolition (Rosa. 199 I) Page 17 of 21 Exhibit 23 62 Hydrodemolition of concrete surfaces and reinforced concrete structures

2.4.7 Steel
fibre reinforcement effects Hydrodemolition of steel fibre reinforced concrete plays a role if industrial floors or. respectively, hydraulic structures are maintained. Effects of steel fibre ment on hydrodemolition processes are investigated by Hu et al. (2004) who pointed out that impact angle determines the influence of reinforcing fibres. At low impact angles (15°) the fibres form 'shadow zones'. as illustrated in Fig. 2.41, that prevent the concrete behind the fibres from being eroded. For this reason. removal rate drops. However. the addition of fibres to a concrete also adds weak interfacial zones between matrix and fibres (Balaguru and Shah. 1992). The pressurised water penetrates these zones and causes a separation of the fibres. Therefore. these zones deteriorate the erosion resistance especially if the material is impinged by jets at vertical angles. Under such conditions. a steel fibre reinforced concrete can even more efficiently be removed by water jets than a corresponding plain concrete; this conclusion is proven in Fig. 2.42. Figure 2.41 Shadow zones. formed behind reinforcement fibres during water jet erosion (Hu et aI.. 2004) Page 18 of 2 1 Exh i bit 23 Fundamentals oj Hydrodemolition 63 1'50 ,.-----------

, i rnpac1 <;rlgl e o l!i* '30* , 6 120 u Q: u.. , E -(1;1... Water j et v e l o c ity in m l s Figure 2.42 EJJect oj steelfibre reinforcement on mass removal (Hu et al., 2004) 2.5 Hydrodemolition model Labus (1984) developed models for estimating depth of cut as well as material removal rate for hydrodemolition applications.

The model for calculating depth of cut is based on non-dimensional terms; it has the following structure: Figure 2.43 shows a plot of this relationship as applied to experimentally estimated data. The correlation fits the data quite well with a correlation coefficient of 0.88. and the constants in Eq. (2.49) can be estimated to K o=9.S1S. and K 1=0. 355. The model was expanded to a rotating nozzle carrier; structure and geometry are illustrated in Fig. 2.44. The final model reads as follows: (2.50) Page 19 o f 21 ---Exhibit 23 64 HydrodemoliLion of concrete surfaces and reinforced concrete structures JIJ r [ i -; .t=-II :>. I 0 Figure 2.43 Verification of Labus' (1984) hydrodemolition model x h V T b b* Figure 2.44 Parameters used in Eq. (2.50) Pa ge 2 0 of 21 Exh i bi t 23 Fundamentals oj Hydrodemolition 65 In contrast to the depth of cut. volumetric material removal rate is a function of time. since the relationship is an instantaneous rate. By integrating over the time. it takes for one revolution of the nozzle carrier head. the average volumetric material removal rate can be estimated. Calculations based on the model showed some good agreements with trends from experimental results; this applies in particular to nozzle diameter. pump pressure. and stand-off distance. However. from the results discussed in the previous Sections. it is clear that the model simplifies the effects of material parameters. Compressive strength alone can not determine the resistance of concrete to hydrodemolition. Aggregate type and size are more important, and at least one of these parameters must be included into Eq. (2.50). Pag e 21 o f 21 Exhibit 24: Hydrodemolition Appendix VIII-2S© 2012. Performance Improvement I ................................................ -...................... E x h ib i t 24 Hydro emolit* a Remov* g Co by James Warner ydrodemolition is a relatively new technology for the moval of concrete. First used in Italy in 1979 -with type equipment -to remove concrete on the Viadotto del Lago, its ment was slow until 1984 , when it was introduced in Canada and Sweden. Only within the last decade has it been commonly used. tion involves impingement of a discrete blast of water under very high pressure in a controlled manner. The concrete is disintegrated into generally small ble as a resu It of both the impact of the water on to the surface and the ization of internal pores, cracks, and voids. Advantages of hydrodemolition The procedure offers many It is much faster than ,. t io ria1 c h ippin g p*n euma t ic rt : is fairly quiet, is free from dust and vi-: brat ion. and re ults i n small size rubble ... . . . . . . . _................ that can be easily handled and reused for surface cover or base material , often without additional processing. demolition is selective in that it will generally find and disintegrate all crete below a given porosity or strength level. Bond surface The greatest advantage, however, is provision of a superior quality upon which to bond new concrete. drod e molition do e not " br u i se" the :. suli i ng -urfac e-:::: i t* d o-e s " n or ca u*s e *a* , network of microcracks in the parent ,, , concrete near the bond line, as do other , : removal methods that involve direct : I n. _: very clean, rough, undulating , high plitude surface profile that provides the maximum obtainable bond surface area. It generally will not damage existing reinforcing steel and will, in fact, clean the reinforcing of all corrosion ucts and other contaminates. Selective removal In addition to removing all porous or low-strength concrete, it will tend to open and rout out remaining cracks that extend into competent material. And when properly controlled in concrete with uniform porosity and strength , it will not damage or remove excessive amounts of good quality concrete that will be left with a well-prepared face for immediate placement of the new overlay. With all these advantages , one might quickly conclude that the introduction of hydrodemolition is truly a blessing. And in most instances it is, but like all good things , there are disadvantages and limitations that sometimes found its use. Disadvantages Large amounts of water are required that not only must be obtained , but dled and disposed of as well. The water must be directed to appropriate areas for collection and controlled so that it does not flow into areas that must main dry. The spent water is usually very alkaline and contains a large amount of suspended solids that will often require neutralization and tion before it can be run into sanitary or storm sewers. Th is can be readily dled by the use of settling and ization tanks. Recycling At least one hydrodemolition tor is recycling the water on some projects , 5 and because it must be very clean and completely free of even minute suspended solids, an extensive reclamation plant is required. Even with the use ofa polishing filter that moves the smallest particles (I to 5 crons in size), the service life of the nozzle and some pump components is shortened due to the high abrasi veness of even very small particles when eling at very high velocities that are herent with the procedure. Frame assembly for hydrodemolition on inclined/vertical surfaces. Removal The demolished rubble is usually pushed into piles on the adjacent molished surface , where it can be dled with a small loader. This is generally a ccomplished with the water pressure of a fire hose or pressure washer. A fine cementitious slurry will remain long after the larger particles have been removed. I f allowed to dry, a very fine powder residue will result. If the residue is not removed , it will have a deleterious effect on the bond of the repair material. It is very hard to move once it has been allowed to dry , but its drying can be precluded by tended washing of the wet surface mediately after hydrodemolition with clean water until the wastewater runs clear. The process will find and pulverize all low strength or deteriorated crete , and unfortunately , even PdQ@.4l of 4 tent concrete that is very porous, regardless of depth. There are many projects where the removal of all tionable concrete is not acceptable due to economic or other considerations, and the removal of significant amounts of competent concrete is seldom sired. This is a frequent problem on structural slabs in which reinforcing is not uniformly distributed, or where rosity and/or strength are high Iy able. This can be a particular problem where a minimum thickness of removal below the reinforcing is required. To obtain the required reinforcing ance in those areas of relatively high competency or strength, those areas of lower strength or lesser quality might be cut excessively deep and in extreme situations , disintegrated for their full depth. The importance of the strength of the concrete is widely recognized in the hydrodemolition industry; however, the significant influence of porosity or microcracking is not. Terms widely used in the hydrodemolition industry to describe concrete are "sound" and sound." Virtually all concrete that is disintegrated in the process is described as low strength or unsound, which ten is not accurate because concrete that is porous or contains microcracks can still be competent and of adequate strength. Application Typical water pressures used in demolition will generally be within a range of 55 to 350 MPa (8000 to 50,000 psi) or more, with water flow rates on the order of 19 to 300 L (5 to 80 gal.) per minute. The amount of work accomplished is dependent on the hydrodemolition energy that is ly the product of the pressure and the flow rate. Also of some influence are the nozzle design, trajectory, and tance from the impingement surface. Low flow rates generally require tively high pressures, whereas a similar amount of removal can be plished at lower pressures combined with higher flow rates. There are mum pressures required, however, that are dependent on the concrete strength and condition. Rock mechanics research has shown that where a minimum threshold sure is required to cause erosion , the rate , and thus depth of removal, is pendent on rock permeability , which is a cross-sectional area of the pores 6 As a general rule, the strength of concrete is directly related to its porosity. Lower strength concrete is usually more rous than high-strength concrete , and because the pressurization of pore space has a great influence on the moval operation, hydrodemolition ciency is thus directly related to the volume of pore space and thus, crete strength. Rules of thumb ing the required water pressure to demolish good qual ity concrete have been offered by various tion equipment manufacturers and tractors. These are generally within a range of 3 to 3-1/2 times the comsi ve strength of the concrete. Almost from the original ment of the process, there have been two different philosophies as to optimal pressure and flow rates. Equipment commonly used in the United States operates either at a pressure of about 117 MPa (17,000 psi) and a flow rate of Exhibit 24 190 to 300 L (50 to 80 gpm) per minute, or so-called ultra-high pressure, about 230 MPa (34 , 000 psi) and flow rate of about 120 L (32 gal.) per minute. crete can be disintegrated equally weJJ with either set of pressurelflow eters, although the lower flow rates that are inherent with the ultra-high sure are more gentle on the concrete. The author suggests that whereas use of the higher flow rate equipment is tical on open structures such as bridge decks , applications in parking tures and other enclosed areas (where both water control and debris removal are difficult), might best be plished with the ultra-high sure/lower flow rate equipment. Primary use Considerably less energy is required to disintegrate concrete that contains large and extensive voiding, such as cracking and microcracking caused by sulfate attack, alkali silica reaction, and similar mechanisms, or delamination or spalling as a result of corrosion of embedded ferrous metals or reinforcing steel. For this reason, hydrodemolition is particularly suited for removal of such deteriorated concrete, and this is its primary use. Rate of removal Concrete removal is dependent on not only the water volume, pressure, and nozzle factors, but also on the rate of movement of the nozzle over the surface. To maintain control of the concrete removal , all of these parameters must be set and consistently maintained. though a hand-held lance can be used for small areas, hydrodemolition of large planar areas is generally facilitated fd g@ f I":nnr:r..t..lnt..rn"hnn" of 4 Exhibit 24 by the use of a controlled "robot" or frame assembly onto w hich one or mor e os cill ati ng or rotatin g nozzles are mounted. Typical robots are se lf-prop e lled , draulically powe red vehicles. The zles are mounted on a transverse bar that is commonly about 6 ft (2 m) long. They traverse back and forth on the bar at a uniform rate that can be adjusted from about 1 to 60 seconds. In tion , the robot moves away from the demolished area in discrete "s teps ," ten referred to as "indexing," which is variable from about 0.25 to 6 in. (6 to 150 mm). The traverse speed, number of traverse s, and length of the step can be set into the controller. which then uniformly manages the operation. Uniformity of removal can be hanced when several rapid traverses are made at a given ste p, instead of a sgle, slow traverse. Computers are used to control the parameters on some chines, while manual settings are used on others. To maximize the efficiency of the diesel engines that power the high-pressure pumps, hydrodemolition equipment i s generally run at a constant pressure and flow rate. When hydrodemoiition is executed in good quality concrete of uniform s trength and free of cracks or cracks. removal wi ll generally be to a reasonably uniform depth. Depending on the s trength of the concrete and the operating parameters that have been ent ered into the on-board controller, moval depths can be set from a few limeters to about 20 cm (8 in.) in a si ngle pass. Obviously, under similar operating parameter s , much greater depths will be removed if the concr e te is deteriorated or contains extensive cracks, microcrack s , or other internal imperfections. The operating parameters will thu s vary from o ne project to another, and often vary between different areas of a given s tructure. Where h ydrotion is used on a repair project, t yp ical practice is to initiall y se t the operatin g parameters b y trial and error prior t o the production work. A small te s t area 3 to 5 m 2 (30 to 50 ft 2) of apparently undama ge d concrete will be disintegrated, with the ment controller set to remove to a depth of about 12 to 25 mm (0.5 to I in.). If the expected results are not achieved. the settings wi II be adjusted and further trials completed until satisfactory sults are obtained. The equipment will then be relocated to a typical area of damaged concrete and a similar small area removed. Any further adjustments required will be made until the desired result is obtained. Ideally, thi s will completel y remove all damaged crete. However , in some cases , this may not be desired or practical. Concrete of varying s trength or a nonuniform distributi o n of internal fects will result in removal to varying depth s, and in some cases , the entire thicknes s of the section. Where aged concrete exists only on the surface and is underlain by uniformly good quality concrete , the parameters can be se t to remove only defective material s. However, if the thickness of the tive concrete or the porosit y or strength of the underlying undamaged co ncrete varie s, periodic adjustment of th e p arameters will be required and able variation of the depth of cut will result. In extreme cases, tion may prove to be an inappropriate removal method. Case studies In one instance , h y dr odemo lition was performed to remove the deteriorated surface concrete of a steel girder crete deck bridge. Following the cal robot trial and error period, an initial production pass was made tween the girders. Removal was as sire d and hydrodemolition appeared to be a wise choice. However, when the next pass was made, which was over a beam , the concrete was bla s ted away for the fu II depth of the deck. The excessive remov a l was due to the fact that the concrete contained many cracks for its fu II depth over the steel girders as a result of corrosion of the closely spaced s hear pins, which were attached to the top of the steel sections. It would have been des i rable to remove th e faulty concrete to full depth, but practicality did not allow th a t. If all concrete bearing on the girders had been removed there would not be any support for the remaining deck sections. Furthermore , environmental st rictions prohibited the discharge of dem olit ion debris under the bridge. drodemol iton wa s not an appropriate removal method for thi s project. In another case , hydrodemolition was specifi e d as the removal method for fective concrete on the decks of a ing str ucture. On commencement of the work , it was found that the depth of terioration varied greatly , an d in many areas the concrete was demolished full depth (blow through). While it was vanta geo u s to find and remove a ll of the deteriorated concrete , a able amount of competent concrete was r emo ved as well. The contractor 's s horing method h a d to be changed, and extensive form work was required , Allnll<::t1 !HIR greatly increasing the cost of the aware of possible variability of the crete porosi ty and/or strength when considering hydrodemol ition. Budget It is believed by many in the industry that the removal depth is related strictly to concrete strength, and that all and contract documents should allow for appropriate additions and ments as applicable. crete disintegrated by the water jet is thus either low strength or While that is sometimes the case, it not true in all instances. Very compe-tent and even high-strength concrete The advantages of hydrodemol ition are can have a system of microcracks, the many, and the ability to remove all con-distribution of which is not necessarily crete that has been subjected to uniform. Also, significant variation of ration, or that which is below an strength or content of entrained or en-approximate strength level is certainly trapped air can exist even in very com-b en e fic ia l. H o w e v e r. w hc n c o n s ider i ng :. *pet e nt con c re t e .... rn e* i n rIuen c e *o*r-s ucn .: tiYdr O*d'emoTiuon , Keep porosity is far greater from the stand-, water will pressurize all voids it is abl e : point of the concrete's susceptibility to
L o access, even those that might exist at : disintegration by high pressure water

a greater depth than the planned remov-. .a l. Likewise, where the compressiv e: fect of high pressure water can be quite s trength, porosity, or defect level of the : variable even on concrete of high and c oncrete is variable, the depth of re-: generally uniform strength.
To com-* *********: pensate for these factors, the settIngs of Any areas that have cracking or ex-the robot may. reqUire frequent adJust-cessive porosity for full depth will likely ment. qualIty of. t.he be completely penetrated. This should finished relies heavily on the ability be considered prior to and attentIveness of the hydrodemolI-tion. Consideration must be directed to tion operator. the I ikel ihood of such occurrences, so Due to these factors, cost overruns that both the budget and timely and claims have occurred on several al action can be taken if necessary. hydrodemolition projects due to sive removal quantities. It is thus im-References portant that designers and specifiers be 1 Hindo. K. R.* In*Place Bond Tesling and Exhibit 24 Surface Preparation of Concrete." Concrefe fernal/anal, V. 12, No.4, April 1990, pp. 46-48. 2. Silfwerbrand, 1., "Improving Concrete Bond in Repaired Bridge Decks," Concrete fional, V. 12, No.9, Sept. 1990. 3. Ingvarsson, H., and Eriksson, B., demolition for Bridge Repairs," Nordisk Betong, No. 2-3, Stockholm, Sweden, 1988, pp. 49-54. 4. Warner, .I., et aI., "Surface Preparation for Overlays," Conerefe InternatIOnal. V. 20, No.5, May 1998, pp. 43-46. 5. Morin, M., and Tuttle, T., "Recycling demolition Wastewater -The Hidden tage," Conerefe Repair Bullefin, V. 10, No.2, March-April 1997, International Concrete Repair Institute, Sterling, Va. 6. Rehbinder, G., "Theory About Cutting Rock With a Water Jet," Rock ivlechonlcs, V. 12, 1980, pp.247-257. Selected for reader interest by the editors. The topic covered by this article was ed at the ACI Seattle, Wash., conventIOn In April 1997. ACI Fellow James Warner is a ing engineer based in Mariposa, nia. His international practice involves analysis and __=--:-, tion of structural, and material He is a member of ACI
364,

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Exhibit 25: MoDot Hydrodemolition Repair of Bridge © 2012. Performance Improvement International Appendix Exhib i l25 MoDOT Research, Development and Technology RDT 02-002 Hydrodemolition and Repair of Bridge Decks R197-025 December, 2002 Page l oE 1 8 Exh i bi t 2 5 TECHNICAL REPORT DOCUMENTATION PAGE I. Report 2 Government Accession No. 3. Recipient's Catalog No. 1.RDT02-002
4. Title and Subtitle 5. Report Date Hydrodemolition and Repair of Bridge Decks December 16 , 2002 6. Performing Organization Code Performing Organization Report No. Rl97-025 7. Author(s)
John D. Wenzlick , P.E. 10. Work Unit No. Missouri Department of Transportation Research, Development and Technology
9. Performing Organization Name and Address II. Contract or Grant No. P. O. Box 270-Jefferson City, MO 65102 12. Sponsoring Agency Name and Address 13 . Type of Report and Period Covered Missouri Department of Transportation Final Report Research, Development and Technology

14. Sponsoring Agency Code P. O. Box 270-Jefferson City, MO 15. Supplementary The investigation was conducted in cooperation with the U. S. Department of Transportation, Federal Highway

16.
The use of modern hydrodemolition equipment for removal of deteriorated concrete and preparation of bridge decks for concrete repa i r. Comparison of hydrodemolition to conventional sawing and jackhammer removal concerning cost and harm to remaining concrete. 17. Key Words 18. Distribution Hydrodemolition , hydroblasting, concrete removal, concrete No restrictions. This document is available to the pub lbridge through National Technical Information Center , Springfield, Virginia 22161 19. Security Classification (of this report) 1 20. Security Classification (of this page) 121. No. of Pages 122. Price Unclassified Unclassified 36 Form DOT F 1700.7 (06/98) Page 2 of 18 Exhibit 25 RI97-025 Hydrodemolition and Repair of Bridge Decks Final Report MISSOURl DEPARTMENT OF RESEARCH, DEVELOPMENT AND BY: John D. Wenzlick, Acknowledgment Pat Martens, Dave JEFFERSON
CITY, DATE SUBMITTED:
December The opinions, findings, and conclusions expressed in this publication are those ofthe principal investigators and the Missouri Department of Transportation; Research, Development and Technology . They are not necessarily those of the U.S. Department of Transportation, Federal Highway Administration. This report does not constitute a standard or regulation. Page 3 of 18 Exhibit 25 EXECUTIVE
SUMMARY
It was the intent of this study to prove that hydrodemolition is a better alternative to removing deteriorated concrete form bridge decks than conventional mechanical methods such as jackhammers. Jackhammers can cause microfracturing ofthe concrete left in place. Microfractures in the remaining deck can cause premature loss of bond in the patches or the overlaid surface to which a large investment has been applied in hopes of getting a rehabilitated bridge deck that will last another twenty to thirty years. MoDOT over the past ten years has experienced extensive cracking and debonding of its dense concrete bridge overlays leading to premature deterioration of the rehabilitated decks, well before the end of their design life. Hydrodemolition could help solve these problems in future bridge rehabilitation projects. Additionally, after the hydro-blasted material is removed, hydrodemolition leaves the substrate deck clean, it removes all corrosion from the rebar, and the deck is ready for new concrete to be poured. Additional mechanical cleaning and sandblasting ofthe concrete surface and rebar is needed with mechanical removal methods. Hydrodemolition has generally been bid cheaper than conventional mechanical methods but is overall more expensive because of mobilization costs and limited availability of hydro blasting equipment and hydrodemolition contractors close to Missouri. Other items like traffic control and staged construction can be an extra cost because it is necessary to have larger areas of bridge deck closed to do hydrodemolition than it is for mechanical methods. The practices of Missouri's adjoining states were surveyed pertaining to the use of hydrodemolition. Most state specifications use it as an equal alternative to mechanical methods. This study looked at hydrodemolition projects done in Missouri, first by maintenance starting in 1996 in the St. Louis area and continuing on maintenance projects there through 1999. It also looked at the first, and so far only, project designating hydrodemolition as the only method of concrete removal let by construction contract on Route 1-44 near Springfield in Green County in 1998. Costs for all the projects done by MoDOT are presented. Costs for hydrodemolition ranged from $ 1.25 to $ 3.50 per square foot ($3.50 bid on the 1-44 construction project mentioned above) compared to $ 28.79 to $ 32.99 per square foot for conventional removal. A study of the relative damage done to the concrete left in place was done using direct tension or pull off tests. Generally the testing showed pulloff strengths around 150 psi (pounds per square inch) versus 125 psi for the mechanically prepared concrete. This was not as high as expected since a Swedish study had shown strengths up to 300 psi. The limited bond testing done did not show large gains in strength over conventional removal but it is believed further testing would show better results. However, hydrodemolition does provide less damage to the remaining concrete and a cleaner surface ready for the patching or overlay concrete to stick to in a third ofthe time as conventional removal. It is recommended that more maintenance and construction contracts be advertised designating hydrodemolition as the only option for removing deteriorated concrete. It is proposed that, on all bridges that meet the criteria for ease of hydro demolition, all contracts in 2003 be let specifYing hydrodemolition exclusively. (It is estimated this would be about twenty five percent (25%) of bridges contracted to be rehabilitated or widened.) This will foster more availability of this equipment and contractors using it. A report on costs savings and life-cycle costs would be prepared from these 2003 jobs to verifY how superior and cost effective hydrodemolition is compared to mechanical methods in ensuring long lasting concrete repairs. Page 4 of 18 Exhibit 25 TABLE OF II LIST OF TABLES II LIST OF FIGURES INTRODUCTION AND OBJECTIVES 1 2 RESULTS AND DISCUSSION (EVALUATION) HYDRODEMOUTION, FALL 1996 HYDRODEMOUTION, 1997 HYDRODEMOUTION, 1998 HYDRODEMOUTION, 1999 BID PRICES FOR HYDRODEMOLITION TECHNICAL APPROACH TESTING PROCEDURES CONCLUSIONS RECOMMENDATIONS PRINCIPAL INVESTIGATOR AND PROJECT MEMBERS AFFECTED BUSINESS UNITS AND PRINCIPAL CONTACT TECHNOLOGY TRANSFER BIBLIOGRAPHY APPENDIX A WORK PLAN APPENDIX B HYDRODEMOLITION SPECIFICATION -JOB J810674 APPENDIX C "GENERAL SPECIAL PROVISIONS -BRIDGES" FOR REPAIRING CONCRETE" Page 5 of 18 Exhibit 25 LIST OF TABLES Table 1: Hydrodemolition Specifications of Other States 1 Table 2: Bid Prices for Hydrodemolition 7 Table 3: Pull-Off Hydrodemolition, 8 Bridge L-868, St. Mary's Way 1I-44, Franklin Co. Table 4: Pull-Off Hydrodemolition, 9 Bridge A-I 74, 1-44 EBL, Greene Co. Table 5: Pull-Off Strength -Hydrodemolition, 9 Bridge A-135RP, 1-70 WBL, S1. Louis Co Table 6: Pull-Off Mechanical Methods, 10 Bridge A-241, 1-270 WBL, S1. Louis Co. LIST OF FIGURES Figure 1: Hydrodemolition machine in action 3 Figure 2: Filtering waste water 3 Figure 3: Self contained vacuum truck 3 Figure 4: Vacuum truck with hose on boom 3 Figure 5: Traffic control and containment of blast water 4 Figure 6: Finished hydrodemolition surface 5 Figure 7: Poor concrete left after hydro demolition at 13,000 psi 5 ii Page 6 of 18 Exhibit 25 Introduction and Objectives Hydrodemolition is a faster, cleaner and better way to remove deteriorated concrete from bridge decks in order to patch or rehabilitate the driving surface. The basic steps in the hydrodemolition of concrete bridge decks are as follows. First scarifYing ofthe original bridge deck is required before hydrodemolition of the surface. Hydrodemolition is done with a computerized, propelled robotic machine utilizing a high pressure water jet stream in the range of 15,000 to 20,000 PSI and usually removes all unsound concrete in one pass. Ifrequired, hand held high pressure wands or 35 lb. maximum jackhammers shall be used in areas inaccessible to the hydrodemolition equipment. The contractor removes the hydrodemolition debris with vacuum equipment before the debris and water is allowed to dry on the deck surface. The contractor will take steps to prevent damage to existing reinforcing steel and not place wheels from heavy equipment, such as vacuum trucks, on areas where the top layer of slab reinforcement has been left unsupported by the hydrodemolition process. After debris is removed the deck surface and patches and the exposed reinforcing steel is usually clean and ready for concrete placement. MoDOT's Job Special Provision (JSP) allows in areas where removal of unsound concrete does not expose the bottom mat of reinforcing in the deck to be patched with latex modified concrete and placed monolithically with the concrete wearing surface. The hydrodemolition process allows several steps needed in conventional removal to be eliminated. Sounding and marking of delaminated areas is not necessary because after the hydrodemolition equipment is correctly calibrated it will automatically remove any delaminated or deteriorated concrete. This eliminates the need to saw cut around patching areas as needed with conventional jackhammer methods. Sandblasting of rusty or dirty reinforcing steel is not needed because it is cleaned at the time of hydro demolition. Because of the very good bonding surface left by the hydrodemolition patches are allowed to be placed, if the bottom reinforcement hasn't been exposed, at the same time as the wearing surface concrete. This step alone eliminates the time and labor needed for a separate patching operation and the time to wait for patches to cure before being able to place the wearing surface. The only additional needs for hydrodemolition are a large water supply and the control of runoff water. It was intended to prove that hydrodemolition is a more efficient and less destructive method than using jackhammers for removing deteriorated concrete from reinforced concrete bridge decks. In hydrodemolition all the deteriorated concrete is removed, the reinforcing steel is cleaned, and the remaining concrete is not left with micro-fractures as it is when jackhammers are used. MoDOT has had a problem over the last ten years or so with premature failures of rehabilitated bridge decks using dense concrete overlays. There have been problems with excessive cracking and with debonding of the overlay from the original deck concrete. These problems have occurred with all types of overlays, latex modified concrete, low slump concrete and silica fume concrete. Curing of the concrete and other factors are causing the cracking problem, but loss of bond could be alleviated by using hydrodemolition instead of conventional mechanical methods of removing deteriorated concrete. Hydrodemolition is more expensive at this time because of the expense ofthe equipment and the short supply of contractors doing this kind of work. For this reason mobilization costs are high, however, these costs have come down recently with more equipment being manufactured and more contractors now getting into this type of work. Page 7 of 18 Exhibit 25 A review of concrete removal practices of the adjacent states was made. Table 1 below lists the states contacted All the states that specity hydrodemolition, allow either it or conventional mechanical methods except Kansas. If a bridge deck is to receive a concrete overlay, Kansas DOT only allows hydrodemolition. Two ofthe states don't specity hydrodemolition at all. Table 1: Hydrodemolition SpeCifications of Other States State Hydrodemolition Specifications Missouri SpeCial Provision if an overlay is involved (includes hydrodemolition as alternate for conventional) Kansas Specification 724 (hydrodemolition only for bridge overlays) Illinois In Deck Slab Repair Specification (includes hydrodemolition and conventional both) Iowa SpeCification 2413 (includes hydrodemolition and conventional both) Arkansas Nothing found Nebraska Does not indicate use of hydrodemolition Technical Approach This study was set up to observe the hydrodemolition process and become more familiar with the equipment and its operation. Through pull-off or direct tension testing before and after removal of the deteriorated concrete and after patching, this study was designed to determine the effectiveness of hydro demolition over conventional jackhammer methods in leaving a better substrate on which to apply new concrete. Hydrodemolition can reduce micro-fracturing while removing all of the deteriorated concrete. Also price comparisons between the two methods were made using costs from several maintenance projects and also one bridge rehabilitation construction project and previous maintenance and contract work. Results and Discussion (Evaluation) Hydrodemolition, Fall 1996 The Missouri Department of Transportation, MoDOT, first tried hydrodemolition for the repair and concrete overlay of a bridge by maintenance contract on S1. Mary's Way over 1-44 in Franklin County just southwest of St. Louis. (Figure 1) The cost was $ 12,000 for one pass of 2 Page 8 of 18 Exh i bit 25 the hydroblast machine over the whole bridge, 5,800 square feet, or $ 2.06/sf. This price included vacuuming up the debris and dumped on site. MoDOT maintenance forces were used to haul the rubble away. MoDOT also had to set up straw bail dams to catch the solids in the water before it was allowed to enter the roadway ditch. The effluent was checked by MoDOT to supply information on turbidity to the Missouri Department of Natural Resources to make sure it passed clean water standards. Figure I: Hydro machine in action. (Note the rubble in Figure 2: Note the straw bails covered with burlap at Front , compared to the milled deck behind.) the end of the bridge to filter waste water. The biggest concern from this first project was about the vacuum truck backing onto the rebar mat and bending it down where concrete was removed below the top mat. The heavy truck (Figure 3) worked all right here. However, if a lot of reinforcing steel is showing, plywood would need to be placed under the truck tires to distribute the load better. Alternately, a hand guided vacuum, or one with a boom (Figure 4), which didn 't have to travel over the rebar could be substituted for the truck. Figure 3: Heavy, self contained vacuum truck . Figure 4: Vacuum truck with hose on boom; can stay Note: vacuum nozzle located in front of the rear wheel off rebar mat but is slower picking up debris. works very well to pick up debris. 3 Page 9 of 18 Exhib i t 25 Hydrodemolition, 1997 A second hydrodemolition project was done again by maintenance contract in the summer of 1997 on Bridge L-896, Franklin County, Rt. 100/1-44 only about a mile from the first bridge. Hydroblasting of 5,800 sf. was done for $ 1.25/sf. or a total price of $ 7250. This bridge received a full concrete overlay like Bridge L-868. It demonstrated that MoDOT cou ld extend the life ofa second bridge deck by relatively low cost hydrodemolition and repair with a dense concrete overlay. On both the 1996 bridge and this one, one step in the repair process, pouring concrete patches before overlaying, was also eliminated by pouring the patches and overlay at the same time (a monolithic concrete placement). Under the same bid, hydrodemolition of unsound concrete and patch ing of 6 other bridges decks on the aging 1-70 corridor in St. Louis was completed in a third of the time of conventional jack hammer repair done by MoDOT maintenance crews. (Figure 5) Prices were bid lump sum for each bridge and depended on the amount of square feet patched, they ranged from $ 1.33 sf. ($ 12/sy.) to $ 8.33/sf. ($ 75/sy.). Repairing these 7 bridge decks (the complete overlay of Br. L-868 plus patching of 6 others) was done in 20 working days using hydrodemolition. It would have taken 60 days by nonnal hand methods. Figure 5: Shows traffic control and containment of blast water while hydroblasting for patches in two center lanes of a four lane bridge. 4 Page lO of 1 8 E xhibit 25 Hydrodemolition, 1998 In 1998 the first construction contract specifying use of hydrodemolition was let for bridges AO 1741 E and AO 1741 Won Route 1-44 , Greene County near Springfield. This was also MoDOT's first contract allowing a monolithic pour after removal of deteriorated deck with a Latex Modified Concrete overlay. This eliminated the usual patching step in between by filling of excavated areas and overlaying with new concrete at the same time. Because of staged construction , this project required two mobilizations of the hydrodemolition equipment. The westbound bridge was closed to traffic in 1998. The whole deck of the westbound structure , 7,100 sf., was completed. The hydrodemol ition contractor returned in early 1999 to do the 7 , 100 sf. of the eastbound bridge (Figure 6). Even though two trips were required, it is believed the bid was lower than expected due to being able to hydroblast a fairly large amount of surface each trip. Also, no traffic control was needed since the bridges were shut down to traffic. Figure 6: Finished hydrodemolition of half (background) of Bridge A0174 E. In the foreground , new latex mod i fied concrete overlay. Not e: 2" core holes in the overlay are where pull-off tests for direct tension were taken. 5 Pa g e 11 of 18 Exhibit 25 Hydrodemolition 1999 Bridge A-185R Ramp on Route 1-70 , St. Louis City was shut down due to construction in the area. MoDOT maintenance forces took this opportunity to again use hydrodemolition work to repair this bridge deck. A maintenance contract was let for hydrodemolition. The cost was $29.09/sy ($ 3.23 /sf) which compared well with the only construction project MoDOT had let with hydrodemolition , discussed above, which bid at $ 31.50/sy ($ 3.50/sf ). Poor concrete and a thin 6 1/2" upper deck on this type box girder bridge made it necessary to make two passes with the hydrodemolition machine set at 13,000 psi. (see Figure 7) One pass at the normal setting of 17,000 -18,000 psi would have blown through the poor quality concrete. Hydrodemolition makes it easier to regulate than conventional methods with regards to how much concrete is removed when it's necessary to patch and keep open a badly deteriorated deck. Figure 7: Poor concrete and a thin 6112" upper deck made it necessary to do hydrodemolition at 13,000 psi. This is after the first pass (Note how clean the re-steel is in the foreground on the left). A second pass with the blaster was necessary to remove the island of unsound concrete left over the rebar in the center of the photo. 6 P a ge 12 o f 18

Exhibit 25 Bid prices for Hydrodemolition On maintenance contracts the bid prices have stayed consistently low $ 1.25/sf. to $3.23/sf. Only one construction project has been let and the price was $ 3.50/sf, this is almost an order of ten times less than mechanical removal, which bid for $ 28.79/sffor partial depth and $ 32.99/sf. for full depth removal. The limiting factor in getting hydrodemolition bid in Missouri has been the lack of contractors and hydro machinery and the need for numerous mobilizations ofthe equipment on most projects. It should be noted that allowing larger areas of deck to be opened up for hydrodemolition may cause additional traffic control costs. A summary ofthe costs of hydrodemolition for the study projects is listed in Table2 below. Table 2: Bid prices for Hydrodemolition Location Date Total Area Bid Price Total Cost Bridge L-868, St. MaryslI-44, Franklin Co. Fall 1996 5,800 sf. $ 2.06/sf.* $12,000 Bridge L-896, Rt.100/1-44, Franklin Co Summer 1997 5,800 sf. $ 1.25/sf.* $7,250 Patching of several bridges on 1-70, St. Louis Summer 1997 $ 12/sy to $ 75/sy ** $ l.33/sfto $ 8.33 /st) Bridge A01741 E&W, 1-44, Greene County 1998 14,220sf. (1580sy.) $ 3.50/sf($ 31.50/sy.) $49,770 1st construction contract specifying use of hydrodemolition. Bridge A-185R Ramp 1-70, St. Louis City 1999 $ 3.23/sf. ($ 29.09/sy.)
One pass over whole bndge , vacuumed up and dumped on sIte. MaIntenance hauled away ** Prices ranged from $ 12/sy to $ 75/sy depending on the amount of area TESTING PROCEDURES
!<! Milling and jack hammering leave micro-fractures in the surface ofthe concrete, which can cause poor bond to patching or overlay material. Note: during surface preparation the milling step cannot be excluded if specifying hydrodemolition because the hydroblasting requires a rough concrete surface to initiate the removal process. Milling is a separate bid item and no savings with regard :*to*mining*are*re"a1izeo"Oy using nyarodemolitioii over*jaCk*liammering.* However,*all micro: . : : fracturing caused from milling is later removed by hydrodemolition leaving a more sound :
substrate.
........................................................................... Direct tension or pull off strength testing was done on each project using the ACI-503R, Field Test for Surface Soundness and Adhesion, method. Testing was performed on the original concrete after milling and either hydrodemolition or jackhammer removal. Additionally, direct tension tests were taken through the overlay and patch material into the original deck after the new concrete reached required strength.
The limited testing performed on these bridges showed hydrodemolition resulting in average pull 7 Page 13 of 18 Exhibit 25* off strengths of the bond between the overlay and the hydro demolition prepared deck to be 151 psi and 166 psi on maintenance work on bridges L-868 and A-135 Ramp respectively. (These pull off tests were taken after milling, hydrodemolition and the deck overlay was placed -see Notes: on Table 3 and Table 5) On the one construction contract using hydrodemolition, the average pull off strength was 121 psi. on Br. A-174. (see Notes: on Table 4) This compares to 80 psi pull off strength on Br. A-241 using jackhammer removal for patching and 140 psi pull off strength on a milled only area. (no jackhammer or hydrodemolition done in this area -see Notes: on Table 6) It was expected to get higher pull off strengths using hydrodemolition as the literature said strengths were up to twice as strong as surfaces using mechanical methods. It is believed that with a larger number oftests and with a more agile testing machine better results wouldl be obtained. The base plate ofthe tester used is very large (1 ft. x 1 ft) and testing on rough surfaces and around rebar made it hard to always ensure it was normal to the surface. Sweden has obtained pull off strengths up to 300 psi on testing of over 300 hydro blasted decks. (Improving Concrete Bond in Repaired Decks. Concrete International, September 1990) Values for MoDOT testing are included in the tables below. Table 3: Pull-OtT Strength -Hydrodemolition Bridge L-868, St. Mary's Way/l-44, Franklin Co. Tested: 1012/97 iCore No. Tension # Pull Off ation of Failure 1 745 237 1/4" into overlay 2 805 256 Interface, 50% old deck 50% in overlay 3 1080 344 1/4" into overlay Interface, only small part of overlay attached 4 230 73 5 I 500 159 Middle of overlay, 1 3/4' down into overlay 6 390 124 Interface about 75% old concrete Avg. Pull Off Strength =199 psi Note: ACI calls for a minimum PO strength of 100psi. Only cores that break off at the interface give a true bond strength; Average of cores 2, 4 & 6 =151 psi. 8 Page 14 of 18 Exhibit 25 Bridge A-174, 1-44 EBl, Greene Co Tested: 07/1611999 (Constructon hydrodemolitrion contract with 1.75 in. latex modified concrete overlay. iLocation No.Core No. Tension #Pull Off DsiLocation of Failure 1 1 180 57 100% in base 1 2 1020 325 100% in base 1 3 420 134 100% interface Avg. Pull Off Strength =172 psi i 2 1 340 108 100% interface 2 2 520 166 Not recorded 2 3 120 ! 38 50% old patch/SO% interface Avg. Pull Off Strength = 104 psi 3 1 320 102 i100% in base 3 2 134 100% in base 3 3 Avg. Pull Off Strength =180 psi Note: ACI calls for a minimum PO strength of 100psi. Only cores that break off at the interface give a true bond strength; location 1, core 3 and location 2 core 1: average 121 psi. Table 5: Pull-Off Strength -Hydrodemolition Pull-Off Strength Bridge A-135RP, 1-70 WBL, ST. Louis Co Tested: 3/01/00 Location No.Core No. lTension # Pull Off Dsi Location of Failure 1 1 760 242 100% in epoxy 1 2 640 204 Interface, 50% in base I 1 3 400 127 100% interface 1 4 980 312 100% in epoxy Avg. Pull Off Strength =191 psi Note: Only cores that break off at the interface give a true bond strength; location 1. core 2 and location 1. core 3 average 166 psi 9 Page 15 of 18 Exhibit 2? Table 6: Pull-Off Strength -Mechanical Methods Stage 3 -Silica Fume Overlay poured March 22, 2000, Control: Mechanical equipment used for concrete removal Location: Bridge A*241 , 1-270 wbl, St. Louis Co. Tested: 05/2412000 Avg. Location No. Core No.
Pull Off. psi Pull Off. psi Location of (Silicafume overlav on top of ibroke in orig. concrete-1 7/8" 1 (sf/patch) sf patch 21/4" 1 3 120 38 4 380 121 broke at epoxy, 2" sf & 2 1/4" limestone patch broke @ interface of overlay & orig. deck, 1 (sf/patch) 32 100 no patch-2" thick 1 1 127 2 400 broke at interface-2"sf,no (Silicafume overlaY on top of milled surface broke @ interface 2Jsound sf) 360 115 verY smooth-21/16" sf overlav broke @ interface w/deck, 5 2 (sound sf) 6 400 127 Interface rough 2 1/2" thick sf broke 100%@interfacew/oria.
deck 2 (sound sf) 7 560 178 interface smooth surface-sf =silica fume overlay Note: Only cores that break off at the interface give a true bond strength; For the cores over patches, core1 and core 2 average 80 psi, Conclusions The follow findings were made from monitoring of various maintenance and construction contracts using hydrodemolition: Cost can range from $ 12/sy ($ 1.33/sf) to $ 75/sy ($ 8.33/sf) depending on the amount of area contracted. 1*********************************************-_******
...*....*...*....*....
,: 2. Hydrodemolition does not cause damage to the good concrete left in place. Milling and : : jack hammering leave micro-fractures in the surface of the concrete, which can cause : **** p.ppsl. .9!.o.v.er!ay.
.**********..***..***
_.*.******** _** **: In direct tension or pull off testing, limited field data has shown pulloff strengths between overlays or patches and surfaces prepared by hydrodemolition of(121-161 psi) slightly higher than a jack hammered surface (80 psi) or a milled only surface (140 psi). Pulloff strengths for hydrodemolition prepared surfaces averaged 150 psi, which was not as high as expected. It is believed a bigger sample is needed and that with more testing the average would rise. Also there were problems keeping the pullofftester at a perfect right angle to surface, which would cause lower readings. Sweden claims of pull off strengths for hydrodemolition prepared decks at least twice as strong as those od decks prepared using conventional methods. Sweeden has used hydrodemolition on over 300 bridges.! Hydrodemolition leaves the rebar and deck ready in one operation. 10 Page 16 of 18 I Exhibit 25 Recommendations 1.) Results of this study show that hydrodemolition should be used on all construction projects where the cost of mobilization isn't prohibitive. Costs can become prohibitive because of many small spread out work zones caused by zoned repairs on structures with concrete superstructures integral with the deck. Costs also go up because of staged construction and difficult traffic control plans, or because hydro demolition equipment isn't available in the area. However, the advantages gained from not damaging the remaining concrete as well as the speed of preparation ofthe existing reinforced concrete will far outweigh any additional costs and can save MoDOT and the contractors money. It is estimated that at least one-quarter ofthe bridge decks contracted by MoDOT for rehabilitation each year meet the criteria that could use hydro demolition and even be more economical than conventional jackhammer methods. It is believed that equipment and the number of contractors available to do hydrodemolition should increase and the bid prices go down as this new technology establishes itself. 2.) Maintenance bridge repair crews statewide should try to employ hydrodemolition whenever possible on bridge decks with good service ratings that are expected to remain in use for a long time. A video recording ofthe process was made on the first bridge using hydrodemolition in the st. Louis district and has been distributed to all district maintenance units to let them familiarize themselves with the process. Principal Investigator and Project Members John Wenzlick was the principal investigator for RDT with help in reporting by Anika Careaga and field testing by Steven Clark Hydrodemolition work in the S1. Louis area was initiated and coordinated by Pat Martens, District Bridge Inspection Engineer. Testing done on 1-44, Greene County project was coordinated through Jim Blackburn, Resident Engineer in Buffalo, Mo. Testing done on the 1-270, S1. Louis County was coordinated through Lucy Smith, Senior Construction Inspector. Affected Business Units and Principal Contact All district maintenance and design personnel as well as Bridge Design should consider the use of new hydrodemolition techniques for repair of bridge decks. John 'JD' Wenzlick in Research, Development and Technology or Pat Martens of District 6 Maintenance can be contacted for further information. Technology Transfer Designers should use this report to promote the use of hydro demolition in areas where it can be expected that the bid price will be close to that of conventional mechanical repair methods. Contractors should be more receptive when they find how much quicker it is and also the little or no preparatory work needed before pouring new concrete. Reduced time and preparation costs should outweigh the higher capital equipment costs as more subcontractors get into the hydrodemolition business. II Page 17 of 18 Exhibit 25 Districts wanting to do hydrodemolition with their own maintenance forces already have an excellent videotape describing the process that was distributed statewide back in 1997. The video covers all steps in the hydro demolition process, just as they were done on the St. MaryslI-44 bridge in Franklin County. Bibliography
1. Silfwerbrand, Johan Improving Concrete Bond in Repaired Decks. Concrete International, September 1990 2. American Concrete Institute, P.O. Box 9094, Farmington Hills, MI 48333, ACI Manual of Concrete Practice, 1997 12 Page 18 of 18 Exhibit 26: Test Report from WJE Appendix VIII-27© 2012. Performance Improvement Exh l b iPage 1 of 15 [iODUIJDIlODOO[llJODOOOOQI]
DDOOOOITIJD DDOOOllil 0 DOO r CJOITIIIJ DO D" CD OODIIITlO mDIJ WJE o i]:JDJIJ r ITJ , [ill] DITIlO D lIDOJIDOJO r DIl January 30, 2012 0 WJE No. 2012.0222 Prepared for: :J r ITIIJ ornO[[D [][!TID O'J 0 [O[[]]ll] DITD rnrn DIt UTIrnUJill Prepared by: o 1 11 1111 1 1 IJOo:::mIlOII!DO r[[DCTIJIIII I II I 11111010 330 Pfingsten Road Northbrook, Illinois 60062 847.272.7400 tel 1847.291 .5189 fax Page 1 of 1 5 Exhibit Page 2 of 15 DO O[iOOJJJOO [[I 0[10 0 o []],OOr DOOITIJDD[[d L.l..L.LJl-'--'LU...L: ooO'[OOrnOO WJE o[],ODJIJrDD DI::rU[1 [IL] O"DDrITIIJ OUIJo Margaret H. Senior OiJJJOJITI CODr[]] January 30,20120 WJE No. 2012.0222 Prepared for: o r[[]]] 0000[0 oO"Do OOD[[[]]] DrOOD[ [111 UIJIJIJ[[]]]OD Prepared by: o OITTlllT"C OITIiIIJ [[[[[]Or OTI OIIL]]IIlIIIITICo] 330 Pfingsten Road Northbrook, Illinois 60062 847.272.7400 tel 1847.291.5189 fax Page 2 of 15 Exhibit 26 Page 3 of ENGINEERS ARCHITECTS MATERIALS SCIENTISTS WJE o o o [ICI[I[!DOL [![JCD DJ[iJDDJ Introduction ................................................................................................................................................... Samples., ....................................................................................................................................................... Point-Count Analysis .................................................................................................................................... Brief Description of Procedures ............................................................................................................. Findings .................................................................................................................................................. Petrographic Examination ............................................................................................................................. Brief Description of Procedures ............................................................................................................. Significant Features ................................................................................................................................ Near-Surface Zone ........................................................................................................................... Secondary Deposits .......................................................................................................................... Concrete Mixture .................................................................................................................................... Paste ................................................................................................................................................. Air-Void System .............................................................................................................................. Aggregate ......................................................................................................................................... Brief Examination of Core F4 ................................................................................................................ Summary and Discussion .............................................................................................................................. Figures 1 through Page 3 of 15 Exhibit 26 Page 4 of 15 ENGINEERS ARCHITECTS MATERIALS SCIENTISTS WJE [I [I 0 LJ [ 0[[1 [! LILILLLiLLJ_'LJ [[I[10 [I[1l'[IOrDCI[IDIIIIJLlId '-'--,_ILILl.LLLLU [IODr[[JJJ[]j]'OO DJ01IJJ cr=i::JOIJr00 o O[[}"o] DDID crODr[[]] O:JJO OIJDDDDOOODIJDD Petrographic studies of two concrete cores, reportedly from the Davis-Besse Nuclear Generating Station in Ohio, were requested by Dr. Yunping Xi, Department of Civil, Environmental and Architectural Engineering, University of Colorado at Boulder, on behalf of Performance Improvement International, in Oceanside, California. According to Dr. Xi, the cores had been taken from the wall of a nuclear containment structure at the power station. Discovery of a crack in the structure raised concern for its cause(s) and also for the general properties ofthe concrete mixture. Neither of the cores had been taken through the crack of concern. At Dr. Xi's request, one of the cores was chosen for petrographic examination, ASTM C856, Standard Practice for Petrographic Examination of Hardened Concrete" and one of the cores was chosen for point-count analysis, ASTM C 457, Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete. According to Dr. Xi, the nuclear containment structure is reportedly approximately 40 years old, and it is not directly exposed to water from the exterior. The crack, age unknown, is reportedly located parallel to and 3 to 4 inches from the exterior surface of the wall. We do not know the locations that the cores had been taken. The required water-cement ratio of the concrete is reportedly 0.51. Dr. Xi has reportedly conducted physical tests of cores from the structure, including compressive strength (approximately 7,600 psi), and splitting tension (approximately 900 psi). In addition, accelerated creep is reportedly underway. The purpose of the petrographic studies was to determine the general properties of the concrete. The purpose of the air-void system analysis was to determine the air content and the parameters of the air-void system, as well as to determine the volumes of the paste and the aggregate. Dr. Xi also requested determination if the properties of the concrete mixture would contribute to the formation of the crack. This subject was briefly addressed. ODMDODDD The two cores received for the studies had been labeled F2-7923-4.5 and F4-791-2.5. The cores each had a diameter of2-5/8 inches. Photographs of the cores in as-received condition are given in Figure 1. Core F2 was 4-3/4 inches long and had a transverse separation that fit together exactly at 2-112 to 3 inches from its top end. Portions of the separated surface appear tear-like and formed-over, and do not go through coarse aggregate particles, suggesting that the separation may be a partial cold joint. The top end of Core F2 exhibited a moderately rough surface texture with exposed sand particles, as shown in Figure 2. Additional examination of the near-surface zone was conducted as part of the more detailed petrographic examination. The bottom end of Core F4 was a fractured surface that went through nearly all coarse aggregate particles in its path. Page40f 15 Exhibit 26 Page 5 of 15 ENGINEERS Davis-Besse Nuclear Generating Station AR.CHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS WJE Page 2 Core F4 was 4 inches long and both of its ends had been saw cut. The core does not appear to have been compression tested. We do not know which end of the core had been closer to the exposed surface, nor the depth from the exposed surface that the core represents. One end of the core exhibited minor amounts of larger entrapped voids and the other end exhibited relatively abundant amounts of voids, as shown in Figures 3 and 4. This variation in consolidation is one indication of consolidation. Brief visual comparison of the cores showed that the concretes appear to be similar, although Core F2 appears to have overall gray paste with some variation in color and Core F4 has more uniform, light tan paste, as shown in Figure 1. DO DrOOl] OOOODIOIJOODOlTJ analysis of one of the cores was requested. This analysis enables determination of the volumes of the components of the concrete, including air content, more closely than is possible by petrographic examination alone. Precisely knowing the volumes of air, paste, and aggregate is helpful to determine if the concrete has a proper air-void system for frost durability and also if the concrete corresponds to its mix design. Dr 1lIIDJ DDOrc:::JIJJlIOITClJJlIr
JDaI Drorn The specimen was analyzed utilizing the modified point-count method of ASTM C 457. In a analysis, a lapped (polished) specimen is placed on a movable stage under a stereomicroscope.
The stage traverses back and forth in regular, automated increments over the entire surface of the sample. Each time the stage stops, the component of the concrete (aggregate, paste, or air void) that falls directly under the microscope cross-hairs is recorded by the operator in a specialized computer program. Each air void that the cross hairs pass over is also recorded. Nearly 2000 points over a minimum area of approximately 12 square inches are counted to obtain a statistically representative sampling of the concrete. OUIdDIDDD Core F4 was chosen for the point-count analysis because it did not contain an internal separation. Two longitudinal slices were prepared from the core to obtain sufficient area to analyze in accordance with the method. Figure 5 shows the specimens of Core F4 that were analyzed. Differentiation between coarse and fine aggregate in this concrete was not readily apparent at the magnification of the analysis; therefore, the total aggregate volume is reported. The results of the point-count analysis are given in the following table, and are discussed in more detail in the remainder ofthe report. DOJDIDlllJDD 0 CrDJIIllllJ[DIJ[]]O DJD[]UJ[] 1111111111111 i DDMOTI 1111 I 1111111111' CrOlllOID o o[[[t0JlJJIj OJ ornCDOOO o IiIOIJ Oil [[]JDJ][]] [[]JerOJ rn:r[ M o:rrrrn IJll' o [[]]l]IJJ [[]J DID CD o 0 []ID []TIl 0 I:nI OJJIJI][[] rnn::r [[]J c:r OJOIlJ o iii CD WI[[]JDJ][]] [[]J Paste 28.7% NA Total Aggregate. 663% NA Air 5.0% Page 5 of 15 Exhibit 26 Page60f 15 ENGINEERS Davis-Besse Nucl ear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS Page 3 WJE D[[llDJllIl] rn DDDDO[]]JfrO DliIODOiIIIDOllIJ IIDcrrn [l]fr[ M IIII'r rn rn:r o [[[[][[[[]]1I1ID OlIO DO D D [ll]J DODD D [Ill:nrorn IDIID c:rrnrn:o D liIm ITilIIDOllIJ lID Specific Surface 207 in.2/in.3 I 2: 600 in.2/in.3 Spacing Factor 0.024 in. :=: 0.008 in. 0000000 CDC OJ [[]]OCMOIJ0 CITD 00 Core F2 was chosen for detailed petrographic examination. Significant features of the core are described first, followed by characteristics of the concrete mixture. Limited examination of Core F4 was also conducted to briefly address differences in the concrete mixture represented by the cores. This discussion is given in the last part of the petrographic examination section. A photograph of the lapped longitudinal cross-section of Core F2 is given in Figure 6. o r[]]J[[l[] ODDrCI[[][[]O[I][][[]rOCD:i DrOOL In a typical petrographic examination, a sample is examined both visually and microscopically in accordance with the applicable procedures of ASTM C856, Standard Practice for Petrographic Examination of Harde.ned Concrete. A petrographic examination consists of a progressive series of qualitative observations that are interpreted to draw conclusions about the composition, quality, and probable cause(s) of a number of problems associated with concrete. A thorough visual examination of a sample is the first step in a petrographic examination. The sample is then generally sliced in half lengthwise to prepare it for more in-depth examination. One of the resultant halves is lapped (polished) to accentuate the appearance of the components of the concrete (cement paste, air-void system, and aggregates). Lapped specimens, as well as freshly fractured surfaces, are examined visually and using a stereomicroscope at magnifications up to about IOOX to further characterize any deterioration and to evaluate the concrete's individual compon ents. A typical full petrographic examination also involves observation of powder mounts of the paste, thin sections ofthe concrete, or both, using a petrographic, transmitting-light microscope at magnifications up to 500X. Examination of these specimens allows the composition of the cement paste, mineral components of the aggregate, and other significant characteristics ofthe concrete to be studied in detail. o OJJOIll.lIIDJ []IIJo::IUJrOOO Petrographic examination of Core F2 revealed a number of significant features about the concrete, including its near-surface zone, and the presence of relatively abundant amounts of secondary deposits. Near-S urface Zone Fine aggregate particles are exposed slightly in relief along the entire exposed surface of Core F2. The surface exhibits a light tan portion and a gray portion; the gray portion is thin and appears to have been applied over the tan section. Closer observation revealed that the tan section, about 1116 to 118 inch thick, is a cement-based coating, and is not water-repellant. The gray portion of the coating is also cement based, contains moderate amounts of polymeric fibers, and has a pronounced water repellant nature. The coating is well bonded to the substrate. Figure 7 illustrates the near-surface zone of Core F2. Page6of15 Exhibit 26 Page 7 of 15 ENGINEERS Davis-Besse Nuclear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS WJE Page 4 The outer approximately 114 to 112 inch of Core F2 beneath the coating is variable, mainly with respect to the paste and also with consolidation. The paste varies widely in color, suggesting a significantly variable water-cement ratio. A number of unconsolidated voids are present in the near-surface zone. These voids range from microscopic up to 3/4 inch in diameter and are irregularly shaped, suggesting a harsh mixture, poor consolidation, or both. Drying-shrinkage microcracks oriented perpendicular to the exposed surface are present. A few microcracks extend to a depth of about I inch, the rest are generally 118 inch deep. Paste carbonation is typically about 1/4 inch; although it is up to 3/4 inch along the deeper drying-shrinkage microcrack and also in a poorly consolidated zone. Discoloration of the paste due to carbonation of the cement paste and an elevated water-cement ratio zone are visible in Figure 7. Based on the characteristics listed above, the general quality of the near-surface zone is considered to be relatively poor. The variations in the near-surface zone continue in to the main body of the concrete, but to a slightly lesser degree. These characteristics are discussed in more detail in the next section. Secondary Deposits Secondary deposits thinly line virtually all of the air voids throughout the concrete in Core F2. The deposits have an approximately equal thickness throughout and appear to consist of ettringite and calcium hydroxide. The presence of these deposits in air voids typically suggests long term exposure to moisture migrating through the concrete. However, the occurrence of deposits lining essentially every void in an approximately equal thickness layer is a somewhat unusual pattern that may indicate an internal reaction. IJ D'JO'DJIIM The paste, air-void system, and aggregate in the concrete mixture represented by Core F2 were examined in detail microscopically to determine their characteristics. The results of the point-count analysis of Core F4 are also discussed in this section because the concretes appear to have a similar characteristics. Paste The volume of the paste represented by Core F4 was measured by point-count analysis to be 28.7 percent, and the volume of the paste represented by Core F2 appears to be about the same as Core F4. Significant color variability of the paste, some of which is visible without a microscope on the lapped cross-section, is present in the concrete. Moderate amounts of small to moderately elongated (1116 to 3/8 inch), soft zones of paste with an elevated to significantly elevated water-cement ratio are present throughout the concrete. Small unconsolidated air voids are commonly associated with these zones, which are generally located adjacent to coarse aggregate particles. Figure 8 illustrates one of these zones, which represent areas of weakness and increased potential for fluid penetration. In addition, minor amounts of zones of dark paste that have an especially low water-cement ratio are present in aggregate indentations. Trace, insignificant, amounts of microcracks were detected in the main body of the paste. The paste appears to be well hydrated, and moderate amounts of relatively coarsely crystalline unhydrated portland cement clinker particles are present. No supplementary cementitious materials were detected in the paste. Optical and physical properties of the paste indicate that the majority of the concrete Page 7 of 15 Exhibit 26 Page 8 of 15 ENGINEERS Davis-Besse Nucl ear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATEIUALS SCIENTISTS Page 5 WJE represented by Core F2 has a low water-cement ratio, estimated to be 0.38 to 0.42. Moderate amounts of areas with an even lower water-cement ratio and an elevated water-cement ratio are also commonly present. Based on the estimated water-cement ratio and the measured volume of the paste in Core F4, the cement content of the concrete is estimated to be 6 +/-112 bags per cubic yard. Air-Void System The measured air content of Core F4 was 5.0 percent. The calculated parameters of its air-void system, namely specific surface and spacing factor, indicate that according to industry standards the concrete does not have an air-void system that is adequate for protection against cyclic freezing and thawing damage in moist conditions. The air-void system of Core F2 appears to be similar to that of Core F4. The concrete is poorly entrained and less-than-optimally consolidated. In addition, the entrained air voids are not uniformly distributed. No large honeycombed zones were detected in the concrete; however, moderate amounts of zones concentrated with larger entrapped voids are present, as shown in Figure 5. Other areas that contain few, if any, air voids are also present. These characteristics were also noted along the circumference of the core A relatively small proportion of the air-void system consists of small, spherically-shaped, air voids that are consistent with entrained air. These voids are sometimes concentrated adjacent to sub-round entrapped voids. The majority of the air-void system consists of small to medium size (up to about 114 inch), spherically to irregularly-shaped voids that are consistent with entrapped bleed water voids or unconsolidated voids. According to ACI 318, Building Code Requirements for Structural Concrete, for concrete subjected to severe and moderate exposure with a 1 inch nominal maximum size aggregate, air contents of6 and 4-112 percent are recommended, respectively. These air contents are normally considered to be -1 and +2 percent by project specifications. We do not know exactly what the exposure environment of the structure is. ACI 318 allows a one percent decrease in air content for concrete that has a compressive strength over 5,000 psi. Therefore, based on air content alone, the 5.0 percent air content of the concrete would appear to be acceptable. However, neither of the parameters of the air-void system meets the requirements for a durable air-void system, as indicated by ACI 201, ACI 211, and Design and Control of Concrete Mixtures (PCA publication). The recommended specific surface for adequate freeze-thaw resistance of concrete is considered to be a minimum of 600 in.2/in.3* The recommended spacing factor of concrete that has adequate freeze-thaw resistance is 0.008 inch or less. The concrete represented by Core F4 does not meet these requirements. Aggregate The coarse and fine aggregate both consist of the same crushed limestone. The use of crushed limestone as the entire fine aggregate is somewhat unusual and likely gave the plastic concrete a tendency to be harsh. Point-count measured the total volume ofthe aggregate (coarse and fine) to be 66.3 percent. The coarse aggregate has a maximum diameter of 1 inch. Particles are generally firm to moderately firm for a limestone, dense to somewhat vuggy (containing numerous voids), fresh (un-weathered), gray to light tan, equi-dimensional to slightly elongated, minimally absorptive, angular to subrounded, fine-Page 80f15 Exhibit 26 Page 9 of 15 ENGINEERS Davis-Besse Nuclear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS WJE Page 6 grained, and relatively pure (minimal amounts non-calcareous minerals). Minor amounts of particles that are moderately soft, absorptive, or both also compose the coarse aggregate. The fine fraction of the aggregate has the same general properties as the coarse aggregate. Overall grading, distribution, volume, and physical and chemical soundness of the coarse and fine aggregates appear to be adequate. Very occasionally, partial rims of pale-orange, carbonated paste surrounding aggregate particles are present. The exact cause(s) of this occurrence is not known, although it could be related to deep penetration of atmosphere into the concrete. o rITIIJ]]JD]O [[][[[[]OilliillIl OrOilliDJ Core F 4 was briefly examined petrographically as part of the point-count analysis and also for general comparison with Core F2. Figure 9 is a photograph of the lapped cross-sections of Cores F2 and F4 for comparative purposes. A full-depth, tight, meandering micro crack extends the full thickness of Core F4. The crack goes through a few aggregate particles in its path, indicating that it most likely did not occur early in the life of the concrete. Air voids in Core F4 contain secondary deposits linings in the same abundance and pattern as those of Core F2. Variability of the water-cement ratio and air-void system are evident in Core F4, although the do not appear to be as common as in Core F2. Additional petrographic examination of Core F4 would be necessary to determine its water-cement ratio and other properties more closely. CJMMO o OIIJ OOilli C:OO 0 OO[!]] CO The concrete, especially Core F2, is moderately variable with respect to its. consolidation, air-void system, and water-cement ratio. Less-than-optimal initial mixing or less-than-optimal remixing after re-tempering are the two most common causes of this type of variability. Localized zones of weakness and higher absorption are expected from the variability. The overall estimated water-cement ratio ofthe concrete was 0.38 to 0.42, which is significantly less than the reported required water-cement ratio of 0.51. The parameters of the air-void system of the concrete represented by Core F4 did not meet industry requirements for freeze/thaw durability. However, the higher apparent strength of the concrete provides resistance to water absorption, which is a key component to freeze-thaw deterioration. The widespread nature of secondary deposits in air voids throughout the length of the concrete given the reported lack of exposure to moisture from outside the structure is usual. Long term exposure to moisture is clearly indicated. Perhaps the environment inside the structure has a high humidity, is warm, or both. No evidence of freeze-thaw deterioration was detected in either core. Dr. Xi reported that the crack of concern was located 3 to 4 inches below the surface and that no cracks are present between the crack and the exposed surface. This pattern is not consistent with cyclic thaw deterioration. Additional cracks would be expected closer to the surface in typical freeze-thaw damage. General properties of a concrete mixture that may promote cracking, include but are not limited to, a high volume of paste, an elevated water-cement ratio, and unsound aggregate. The overall volume of paste represented by this concrete is not considered to be high. A paste volume greater than approximately 30 to 32 percent would be considered to be relatively high. An elevated water-cement ratio may promote cracking due to high shrinkage. The overall estimated water-cement ratio of the concrete is considered to Page 9 of 15 Exhibit 26 Page 1 0 of 15 ENGINEERS Davis-Besse Nuclear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30 , 2012 MATERIALS SCI ENTlST, WJE Page 7 be low. The crushed limestone aggregate appears to be chemically and physically sound. In general, variability in concrete may lead indirectly to cracking if areas of poor consolidation , elevated cement ratio, or concentration of air voids are extensive; however, this does not appear to be the case in the concrete represented by the cores. Many other factors may contribute to the formation of a crack, such as reinforcement configuration and structural causes. [fmore insight into the cause(s) of the crack or to the extent of variation in the concrete is desired, petrographic examination of additional cores is recommended, including cores taken through the crack. Page10of15 Exhibi t 26 Page 11 of 15 ENGINEERS Davis-Besse Nudear Generating Station ARCHITECTS Petrographic Studie s of Concrete from Containment Structure MATERIALS SCI ENTISTS January 30 , 2012 Page 8 WJE Figure 1. Cores in as-received condition. Core F4 (top) is overall light tan and Core F2 is more gray. Figure 2. Exposed end of Core F2 , showing sand particles e./evated slightly in relief above the coating. The gray and tan portions of the surface are readily apparent. P age 11 of 15 Exhibit 26 Page 12 of 15 ENGINEERS Davis-Besse Nuclear Generaling Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS WJE Page 9 Figure 3. One of the cut ends of Core F4. Relatively abundant amounts of entrapped air voids are visible. The other saw cut end of the core is shown in the next figure. Figure 4. Other cut end of Core F4 showing one relatively large entrapped void (arrow) and two fresh-appearing chips off the , side of the core that were likely produced by the coring or cutting operation. Page 12 of 15 Exh i b i t 26 Page 13 of 15 ENGINEERS Davis-Besse Nudear Generating Station ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCI ENTISTS WJE Page 10 Figure 5. Lapped cross-sections of Core F4 that were analyzed by point-count analysis. The bottom approximate half of the concrete shows significant amounts of entrapped voids , including one larger unconsolidated void in the specimen on the l eft, while the, upper halves show less air voids. Figure 6. Lapped cross-se c tion of Core F2. The exposed surface of the core is on the left side of the photograph. Page 13 of 15 Exh i bit 26 Page 14 of 15 ENGINEERS Davis-Besse Nudear Generating Slat ion ARCHITECTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCIENTISTS Page I I WJE Figure 7. Near-surface zone of Core F2. For scale, the specimen is 2-112 inch es wide. The most prominent feature, is the pale-orange discoloration of th e paste caused by carbonation. The deepest depth of carbonation is indicated by the yellow a170W. A numb er of unconsolidated air voids are present up to a depth of 3/ 4 inch on th e left half of the near-surface zone. The red arrow indicates one discontinuous string of unconsolidated voids. One section of the coating is shown in by the green arrow. Page 1 4 of 1 5 Exhibil2 6 Page 15 of 15 ENGINEERS Davis-Besse Nuclear Generating Station ARCHIHCTS Petrographic Studies of Concrete from Containment Structure January 30, 2012 MATERIALS SCI ENTISTS Page 12 WJE Figure 8. Closer view of Core F2 showing water-cement ratio variation in the paste. As indicated by the arrow, an elongated zone (about 1 inch long) of light-colored elevated water-cement ratio paste is located below an aggregate. particle. Figure 9. Lapped cross-sections of Cores F2 (top) and F4. Slight differences in paste color are evident. Core F2, on top, exhibits overall more gray and light-colore.d paste, while Core F4 exhibits more uniformly-colored tan paste. Page 15 of 1 5 Exhibit 27: 347R-63 Guide to Form Work © 2012. Performance Improvement International-Appendix Exhibit 27 TITLE NO. 64*33 Proposed Revision of ACI 347-63: Recommended Practice Concrete Reported by ACI Committee 341 WILLIAM R. MARTIN W. BOLL JACOB FELD HARRY L. SCOGGI N GEORGE F. BOWDEN DAVID E. FLEMING P. R. STRATTON PETER D. COURTOIS VICTOR F. lEABU WILLIAM H. WOLF WILLIAM R. DAVIS, JR. JOSEPH R. PROCTOR, JR. GEORGE J. ZIVERTS PAUL F. RICE Presents brief introductory statement on the need for formwork standards based on the fact that 35 to 60 percent of the total cost of the concrete work in a project in the United States is in the formwort A section is given on engineer-architect specifications noting the kind and amount of specification the engineer or architect should provide the contractor. Since the committee concludes that formwork design and engineering. as well as construction. must be the responsibility of the contractor. the recommendations contained in the report are directed to that group. However. an understanding of these recommendations by engineers and architects will aid these groups in their specification functions. The report is divided into five chapters: I. Design. 2. Construction, 3. Materials for Formwork.
4. Forms for Special Structures.
and S. Formwork for Special Methods of Construction. Keywords: aggregates; aluminum; anchors; architectural concrete; bridges tures); buildings; canal linings; civil defense; coatings; composite construction; concretes; construction; construction materials; culverts; drawings; falsework; board; folded plates; form removal; formwork (construction): glass fibers; hangers; inserts; insulating board; loads (forces); lumber; mass concrete; paperboard; parting agents; plastics; plywood; precast concrete; preplaced aggregate concrete; pressure; prestressed concrete; reinforced concrete; roofs; safety; safety factor; shells (structural forms); shelters; shoring: slipforms; specifications; steels; structural design; supports; ties; tolerances; tunnels (transportation); underground construction; underwater construction; viaducts. Page 1 of 8 ACI JOURNAL! JOl Y 1967 331 Exhibit 27 Need for Standard Engineer-Architect Specifications Chapter l-Design l.l-General 1.2-Loads 1.3-Design considerations 1.4-Drawings l.5-Approval by the engineer or architect Chapter 2-Construction .. 2.I-Safety precautions 2.2-General practices 2.3-Workmanship 2.4-Suggested tolerances 2.5-Falsework and centering 2.6-Adjustment of formwork 2.7-Removal of forms and supports 2.8-Shoring and reshoring for multistory structures NEED 338 Chapter 3--Materials and Formwork 352 3.I-Discussion 339 3.2-Properties of materials 3.3-Accessories 3.4-Form coatings or release agents 340 Chapter 4-Special Structures 355 4.I-Discussion 4.2-Architectural concrete 4.3-Bridges and viaducts 4.4-Composite structures 4.5-Folded plates. thin shells, and long span roofs 4.6-Mass concrete 4.7-Underground structures 344 Chapter 5-Formwork for Special Methods of Construction .. 361 5. I-Recommendations 5.2-Preplaced aggregate concrete 5.3-Slipforms 5.4-Permanent forms 5.5-Forms f.or prestressed concrete tion 5.6-Forms for precast concrete construction 5.7-Use of precast concrete for forms 5.8---Forms for concrete placed under water FOR STANDARD Since the cost of the form work for a concrete structure may be 35 to 60 percent of the total cost of concrete work in the project, its design and construction demand sound judgment and ning to achieve adequate forms that are both economical and safe. The engineer or architect responsible for the successful completion of any concrete structure usually will include in his specifications provisons for stripping time, ing of concrete in place, inspection, and approval of form work procedure which could affect the strength and appearance of the completed structure. Neat, well-built, heavily braced forms may still fail due to inadequately tied corners or cient provision against uplift. Form failures have occurred when shoring has been improperly spliced, inadequately cross braced, or was wise inadequate to resist all possible stresses. Shores supported on previously completed floors usually can be assumed to have equal unit ing. However, shores supporting forms for the first level above ground often are supported on "mudsills" and may not have uniform bearing. This condition may occur when mudsills rest on soft ground, on backfill recently placed and perhaps softened by surface water, or on frozen ground which may thaw out in numerous ways. Unequal settlement of mudsiIls seriously changes shore reactions, and may cause serious ing of shores which do not settle as much as others. Proper engineering design of formwork often saves contractors more than the saving from the use of poorly designed Iorms. Formwork is erally more economically constructed on the ground and under the contractor's yard tion than in the air under field conditions. A carpenter not experienced in form work may find it difficult to conceive of forms as pressure sels which need to be adequately tied together, braced, and anchored to resist uplift and to be capable of resisting forces in several directions. Proper detailed instruction is therefore necessary. If working drawings are made for form work, the necessary detailed study of the contract drawings may uncover omissions and dimensional errors. Field work is expedited and the tural engineer can see how his design is being interpreted by the contractor. Other benefits may be shorter job duration. avoidance of delays in field operations, more efficient re-use of forms, and better utilization of material and men. There should be "notes to the erector" on such drawings to eliminate need for referring to specific field customs. Page 2 of 8 ACI JOURNAL I JULY 1967 338 Exhibit 27 TABLE 3.2 (cont.I-FORM MATERIALS AND STRENGTH DATA FOR DESIGN ..-------_... Principal use Specifications and design data sources Item Plastics: Polystyrene PQlyethylene Polyvinyl chloride Rubber Form ties. anchors, and hangers Plaster Coatings Steel joists Steel frame shoring Form insulation 3.3.2-Recommendations FQrm liners for decorative concrete Form lining and void forms For securing formwork against placing load*s and pressures Waste molds for architectural concrete Facilitate form removal Formwork support Formwork support CQld weather protection of concrete 3.3.2.1-Recommended factors of safety for ties, anchors, and hangers are given in tion 1.3.1. Yield point of the material should not be exceeded. 3.3.2.2-The rod or band type form tie, with supplemental provision for spreading the forms and a holding device engaging the exterior of the form, is the common type used for light construction. The threaded internal disconnecting type is more often used for formwork on heavy struction such as heavy foundations, bridges, power houses, locks, dams, and architectural concrete. Removable portions should be of a type which can be readily removed without age to the concrete and which leave the est practicable holes to be filled. Where ties are permitted in construction of water-retaining structures, they should be signed to prevent seepage or flow of water along the embedded tie. Although there is no general uniformity at the present time,* a minimum specification for form ties should require that the bearing art::a of external holding devices be adequate to prevent severe crushing of form lumber. 3.3.2.3-Form hangers must support the dead load of forms, weight of concrete, and struction and impact loads. Form hangers should be symmetrically arranged on the porting member to minimize twisting or tation of supporting members. Manufacturers' data Manufacturers' data Manufacturers' specifications; see this standard for recommended ASTM Manufacturers' recommendations Manufacturers' specifications Section 1.3 of safety factors "Standard Specifications and Load Tables for Open Web Steel Joists," Steel Joist Institute "Recommended Steel Frame Shoring Erection Procedure," Steel Scaffolding and Shoring stitute: also manufacturers' data ACI 306-66 and manufacturers' specifications 3.3.2.4-Where the concrete surface is to be exposed and appearance is important, the proper type of form tie or hanger which will not leave exposed metal at the surface is essential. 3.4--Form coatings or release agents 3.4.1-Form coating-Form coatings or sealers are usually applied in liquid form to contact faces either during manufacture or in the field to serve one or more of the following purposes: (a) Alter the texture of the contact surface (b) Improve the durability of the contact surface (c) In addition to (b) above, to facilitate lease from concrete during stripping (d) Seal the contact surface from intrusion of moisture. 3.4.2-Release agents-Form release agents are applied to the form contact surfaces to prevent bond and thus facilitate stripping. They may be applied permanently to form materials in facture or applied to the form before each use. When applied in the field before each use, care must be exercised to prevent coating adjacent construction ioint surfaces or reinforcinlt steeL 3.4.3-Manufacturers' ufacturers' recommendations should be follow*d in the use of coatings, sealers, and release agents, but independent investigation of their ance is recommended before use. Where surface treatments such as paint, tile adhesive, or other coatings are to be applied to formed concrete surfaces, be sure that adhesion of such surface treatments will not be impaired or prevented by use of the coating. sealer, or release agent. ACI JOURNAL I JULY 19'fP e 3 of 8 354 dling the form during erection or tion for concrete placement plus the method of bracing and. anchorage during normal operation. 4.7.2.2.4-In the case of the tunnel arch form, whether it is intended for use with the unit or bulkhead system of concrete ment or is restricted to use with the tinuously advancing slope method (see tion 4.7.2.3). 4.7.2.2.5-When placement of concrete by pumping or pneumatic methods is pated, the capacity and working pressure of the prime mover and the size, length, and maximum embedment of the discharge line should be as assumed in the design. Also, when the design provides for a method of placement other than by sustained pumping via a buried slick line, it should be clearly stated that the design pressures would be exceeded if sustained pumping were adopted. 4.7.2.3-Construction--The two basic ods of placing a tunnel arch entail problems in the construction of the form work that require special provisions to permit proper re-use. These two basic methods are commonly known as the "bulkhead method" and the ously advancing slope" method. The former is used exclusively where poor ground conditions exist, requiring the lining to be placed concurrently with tunnel driving operations. It is also used when some factor, such as the size of the tunnel, the introduction of reinforcing steel, or the location of tion joints precludes the advancing slope od. The advancing slope method, a continuous method of placement, usually is preferred for tunnel driven through competent rock, ing between 10 and 25 ft in diameter and at least 1 mile in length. The arch form for the bulkhead method is usually fabricated into a single unit between 50 and 150 ft long which is stripped, moved ahead, and re-erected using screw jacks or hy-Exhibit 27 draulic rams. These are permanently attached to the form and supporting traveling gantry. The arch form for the continuously advancing slope method usually consists of eight or more sections that range between 15 and 30 ft in length. These are successively stripped or lapsed, telescoped through the other sections and re-erected using a form traveler. Although the minimum stripping time for tunnel arch forms usually is established on the basis of experience, it can be safely termined by tests in the laboratory. It is ommended that at the start of a tunnel arch concreting operation, the minimum stripping time be 12 hr for exposed surfaces and 8 hr for construction joints. If the speCifications provide for a reduced minimum stripping time based on site experience, such reductions should be in time increments of 30 min or less and should be established by laboratory tests and visual inspection and surface scratching of sample areas exposed by opening the form access covers. Arch forms should not be stripped prematurely when unvented ground water seepage could become trapped between the rock surface and the concrete lining. 4.7.2.4-Materials -The choice of materials for underground form work usually is cated on the shape, degree of re-use and bility of the form, and the magnitude of pump or pneumatic pressures to which it is subjected. Usually, tunnel and shaft forms are made of steel, or a composite of wood and steel. Experience is of paramount importance in the design and fabrication of a satisfactory tunnel form, due to the nature of the pressures veloped by the concrete, placing techniques, and the high degree of mobility usually quired. When re-use is not a factor, plywood and tongue-and-groove lumber sometimes are used for exposed surface finishes, but more sideration may be given to wood sheathing cause the high humidity often precludes the normal shrinkage and warping. CHAPTER 5-FORMWORK FOR SPECIAL METHODS OF S.l-Recommendations The applicable provisions of Chapters 1, 2, and 3 also apply to the work covered in this chapter. S.2-Preplaced aggregate concrete 5.2.l-Discussion-Preplaced aggregate concrete is made by injecting (intruding) mortar into the voids of a preplaced mass of clean, graded gregate. For normal construction the preplaced aggregates are wetted and kept wet until the in-Ael JOURNAL / JULY 1967 jection of mortar into the voids is completed. In underwater construction, the mortar displaces the water and fills the voids. In both types of struction this process can create a dense concrete having a high content of coarse aggregate. The injected mortar contains water, fine sand, portland cement, pozzolanic filler, and an tive designed to increase the penetration and pumpability of the mortar. The coarse aggregate is similar to coarse aggregate for conventional pa g 36 f of 8 Exhibit 27 concrete. It is well washed and graded from % in. to the largest size practicable. After compaction in the forms, it usually has a void content ing from 35 to 45 percent. 5.2.2-Recommendations 5.2.2.1-Design considerations 5.2.2.1.1-Lateral pressure of Due to the method of placement, the lateral pressures on formwork are considerably higher than those developed for conventional concrete as given in Section 1.2.2. Forms, ties, and bracing should be signed for the sum of (a) The lateral pressure of the coarse aggregate as determined from the lent fluid lateral pressure of the dry gregate using the Rankine or Coulomb theories for granular materials; or a liable bin action theory; and (b) The lateral pressure of the jected mortar as an equivalent fluid weighing 130 lb per eu ft. The time quired for the initial set of the mortar (from 6 to 24 hr) and the rate of rise (1 to 2 ft per hr) should be ascertained. The maximum height of fluid to be assumed in determining the lateral pressure of the mortar is the product of the rate of rise (ft per hr) and the time of initial set in hours. The lateral pressure for the design of form work at any point is the sum of the pressures determined from Steps (a) and (b) for the given height. 5.2.2.2-Construction-In addition to the visions of Chapter 2, the forms must be ly "mortar-tight" because preplaced aggregate concrete entails forcing mortar into the voids of the coarse aggregate. The increased lateral pressure usually requires that the ship and details of formwork be of better quality than form work for conventional crete. 5.2.2.3 -Materials for form work -and-groove lumber is preferred for exposed surfaces; the joints between boards permit the escape of traces of mortar. For unexposed faces, mortar-tight forms of steel or plywood are acceptable. Prefabricated panel-type forms usually are not suitable because of the culty in making mortar-tight seals between panels. Absorptive form linings are not ommended because they permit the coarse aggregate to indent the lining and form an regular surface. Form linings, such as board on common sheathing, are not successful because they do not withstand the external form vibration normally required. 5.3-Slipforms 5.3.1-U1SCUSSlon-=Placing of concrete by use of slipforms is similar to an extrusion process. Plastic concrete is placed or pumped into the forms, and the forms act as moving dies to shape the concrete. The rate of movement of the forms is regulated so that the forms leave the formed concrete only after it is strong enough to retain its shape while supporting its own weight. work of this type can be used for vertical tures such as silo and storage bins, bridge piers. shaft type buildings, water tanks, and missile launchers or for horizontal structures such as tunnel inverts, water conduits, drainage nels, canal linings, and paving. Sometimes there may be fixed forms on one side (such as ing, rock, earth, or existing masonry) and a ing form on the other. For other types of work. there are sliding forms on both sides. Vertical slipforms are usually moved by jacks which ride on smooth steel rods or pipe bedded in or attached to the hardened concrete. whereas horizontal slipforms generally move on a rail system or on a shaped berm. Working decks, concrete supply hoppers. and worker's or finisher's scaffolding, where required, are tached to and carried by the moving form work. The vertical or horizontal movement of forms may be a continuous process carried on 24 hr of the day until the structure is completed, or in a planned sequence of finite placements. This section is divided into two parts: vertical sLiptorms; and horizontal sliptorms such as used on drainage channels and canal linings. Slipforms used on such structures as tunnels and mine shafts should comply with the cable provisions of Section 4.7. Slipforms used on mass concrete structures such as dams should comply with the applicable provisions of tion 4.6. 5.3.2-Recommendations 5.3.2.1-Vertical slipforms 5.3.2.LI-Design considerations-Slipforms should be designed and constructed and the sliding operation should be carried out under the immediate supervision of a person or persons experienced in slipform work. In the design of the forms in which jacks on vertical rods are used, care must be taken to place jacks in such a manner that the vertical loads are as nearly equal as possible and do not exceed the safe capacity of the jacks. The steel rods or pipe on which the jacks climb or by which the forms are lifted should be especially designed for this pose. These rods must be properly braced where not encased in concrete. Jacking rods or pipes may be left in concrete or with-ACI JOURNAL I JULY 19fpe 5 of 8 362 Exhibit 27 jacks. Knee braces should be provided for drawn as conditions permit but splices and top wales where span between jacks low bond value must be given special ceeds 6 ft or where vertical loads are un*sideration if they are to be used as usually heavy. .forcement. (b) Lateral pressure of concrete-The The design of the yokes must provide for eral pressure of fresh concrete to be used in adequate clearance to install horizontal designing forms, ties, bracing, and wales may inforcing bars and embedments in their be calculated as follows: rect locations 'prior to their submergence in the rising concrete. 6000R The hydraulic-electric jacking system, P = Cl + which provides for the precise simultaneous movement of the entire form in small where selected increments of approximately 1 in. Cl = 100* at 5 to lO-min intervals, is recommended for P = lateral pressure, psf large structures, especially when single units R = rate of concrete placement in ft per hr are involved. Lateral and diagonal bracing of forms must T = temperature of concrete in the forms. be provided to insure that the shape of the degF structure will not be distorted beyond Wales must be adequately nailed or bolted lowable tolerances during the sliding together to transmit shear due to lateral tion. pressure of concrete and vertical posts should When slipforms are used for single unit be placed between wales at lift points. structures in excess of 50 ft diameter, they are usually segmental, or are provided with a substantial center guide made of steel or concrete, to overcome the latent uncertainty of maintaining correct alignment of an wise unguided form. Drawings should be prepared by a petent and experienced engineer employed by the contractor, showing the jack layout, form work. workinQ" deek!!. and !leAffnlih, 5.3.2.1.2-Loads (a) Vertical loads 1. In addition to the dead loads, live loads assumed for design of decks should not be less than the following: Sheathing and joists. ..75 psf or concentrated buggy wheel loads. whichever is the greater and wales ..40 2. Where working decks are used as a bottom form for cast-in-place tion, the deck must be designed for the dead load of the concrete construction plus any superimposed loads, and in no case less than the design loads given in Section 1.2. The deflection of the working deck should not exceed Vs in. or 1/360 of span, whichever is greater. 3. Vertical loads and possible torsional forces resulting from deck loads and tion of concrete on the forms must also be considered since the forms must act as trusses for the vertical loads between ACI JOURNAL I JULY 1967 5.3.2.1.3-Construction and Forms should be a minimum of 3 ft 6 in. hight and should be constructed of at least I-in. board, o/s-in. plywood, 10-gage mum steel sheets, or other approved rial. The I-in. boards should be straight grained and center-matched and placed with the grain running downward and boards spaced 1/16 to % in. apart to allow for sion when they become wet Forms should be erected with slight draft, particularly for the inside faces so that the form is wider at the bottom than at the top. Timber wales should be of 2-or 3-ply lumber at least one ply of which will be in. material. The minimum depth of mental wales for curved walls should be 4% in. at the center after cutting. Special care must be taken in building the forms and arranging the jacks so that the forms will draw straight and true without strain or twist. To avoid unplanned cold joints, especially when such an occurrence would adversely affect the integrity of the structure, it is essential that reserve jacking and placing eqUipment and standby
It Is felt that <'1 = 100 Is justified because vibration is slight in slipform work. since the concrete is placed in shallow layers of 6 to 10 In. and because there is no revlbratlon.
However. for some applications such as for gaotlght or containment stll'llctures. additional vibration may be required to achieve maximum ity of the concrete. In ouch cases, the value of C1 should be increased to 150, tThe minimum height Is a function of the rate of sUpping (ft per hour) and the time required for the concrete to gain lup,sr;:u some working space in the top dl the form for placing of crete and reinforcement. Fonns less than ft high are believed to be dangerously shallow. Forms as high ill! 6 it may be required when low temperature or slow setting concrete is specified. Pa<J636 of 8
service equipment is immediately avaIlable to maintain a continuous operation. 5.3.2.1.4-Tolerances-Maximum variation in wall thickness should not exceed +/- % in. for walls up to 8 in. thick nor +/- in. for walls thicker than 8 in. The maximum viation of any point on the slipform with respect to a vertical projection of a ponding reference point at the base of the structure should not exceed 1 in. per 50 ft of height. This is the total deviation which may be composed of translational and rota. tional components. 5.3.2.1.5-Sliding operation-Maximum rate of slide should be limited by the rate for which the forms are designed. In addition, both maximum and minimum rates of slide must be determined by an experienced form supervisor to meet changes in er, concrete slump, and workability, and the many exigencies which arise during a slide and which cannot be predicted accurately beforehand. A man experienced in slipform construction must be present on the deck at all times during the slide operation. Forms must be leveled before and after they are filled and must be maintained level throughout the slide. Care must be taken to prevent drifting of the forms from ment or designed dimensions and to prevent torsional movement. xperience as sown t at a p um ne or optical plummet used in conjunction with a water level system serviced by a central reservoir is effective in maintaining the form on line and grade and for positioning o enin and embedded items. Alignment and plumbness of structure should be checked at least once during every 8 hr that the slide is in operation and prefer* ably every 4 hr. In work that is done in separate, intermittent slipping operations, a check on alignment and plumbness should be made at the beginning of each slipping operation. 5.3.2.2-Horizontal slipforms for tunnel verts. drainage channels, canal linings, and highways.'" 5.3.2.2.1-Tunnel inverts-Linings for nel inverts often are constructed in a tinuous longitudinally operating method of placement. The transverse section of the vert usually is curved to a prescribed shape. The best way to hold such a shape and at the same time obtain good vibratory solidation of the higher areas along the side forms is to use a heavy weighted slipform supported on the fixed side forms and hav* ing a length equal to or greater than the Exhibit 27 width of the invert. The slipform is forward by winches. The concrete is livered by pump and pipeline or belt and is placed and vibrated ahead of the slipform. If arch form are inserted in the invert concrete ately behind the slipform, care should taken to insure that they are properly bedded in the wet concrete without ing the newly formed 5.3.2.2.2-Drainage channels-Linings drainage channels and canals may be structed in either a planned sequence of placements or a continuous operating method of placement. In a sequence of finite placements the may range from hand operations for laterals where the concrete may be and spread on the sides and bottom, to larger channels where the lining may placed in alternate sections. In the latter, bottom slab is placed first to provide port at the toes of the side An efficient placement of concrete slopes is accomplished by use of a unvibrated steel-faced slipform screed 27 in. wide in the direction of The screed may be pulled up the slope equipment located on the or by hoists mounted on the slipform. The crete vibrators should be manually just ahead of the slipform rather mounted on the form. If the form is brated, this procedure will cause a swell the finished surfa'Ce emerging from the ing (a) Small channels and canals-A plified type of slipform machine has been used with good results. This machine is held to grade and line by a steel pan, shaped to fit the previously prepared cavation section, and is pulled forward by an external source of power. Behind the pan and immediately preceding the form is a transverse, compartmented trough for uniformly distributing the mix. This type of form which depends on the subgrade for its support is applicable for placing only unreinforced concrete lining. (b) For reinforced linings and also for medium-sized canal linings, more elaborate slipform machines are required. A work, traveling on rails, or a tractor er assembly on the berm of the drainage channel or canal, supports the working platform, the distributor plate or drop *The simplified type of sllpform I. a relatively minor ture; Its design Is straight-forward 'and is not discussed here. The material in this subsection deals with the design and construction of the more elaborate slipform structures. Ael JOURNAL I JULY 1961age 7 of 8 chutes, the compartmented supply trough, vibrator tube in the bottom of the trough, and the slipform. The slipform is a steel plate, curved up at the leading edge, tending across the bottom and up the slopes of the canal and shaped to form to the finished surface of the lining. When a distributor plate is used, it is fastened to the leading edge of the form and extends upward on a steep cline to the working platform. On some of the machines, a continuous row of pers in the working platform feed into drop chutes, each supplying one ment of the trough below. Concrete is dumped, usually from a shuttle car on the working platform, and is guided to the trough below by the distributor plate or the drop chutes. As the concrete passes out at the bottom of the trough and under the slipform, it is consolidated by a vibrating tube parallel to and a few inches ahead of the leading edge of the form. Consolidation must be accomplished as the concrete passes under the slipform. Proper consolidation cannot be obtained by vibrating the slipform of a lining machine, apparently due to lack of means to supply additional concrete needed to fill the voids. The trailing edge of the slipform is usually adjustable to positions somewhat lower than that of the leading edge. This improves consolidation and tends to mold the concrete more ly to the subgrade. Too low a setting of the trailing edge causes tearing, rather than smoothing, of the surface. On some machines, the slipform is followed within a few feet by an "ironer" plate 16 x 20 in. wide, which, under favorable conditions, leaves a surface that requires little or no hand treatment. (c) For large channels (bottom widths of 50 to 110 ft) it is impractical to build machines to span the entire waterway prism. The slope paver is a mounted slipform which places the crete lining on one side slope and the adjacent 8-10 ft of the invert. After the opposite side slope is similarly completed, the invert is finished by horizontal pavers. All three operations are kept on line and grade electronically through sensors ing guide wires. (d) The slipform used for highways is similar in principle to the slope form pavers. No fixed side forms are required as the side forms of the machine slide ACt JOURNAL I JULY 1987 Exhibit 27 forward with the paver leaving the slab edges unsupported. The concrete is posited either on the sub grade ahead of the paver or into a hopper box. Following spreading by a dozer-type strike-off, the concrete is consolidated by vibration and shaped by an extrusion plate or meter. Flat, parabolic, or hip roof crowns can be provided with a quick change device for transitions in and out of horizontal curves. Surface elevations can be maintained by electronic controls. 5.3.2.2.3-Design considerations-This cialized formwork shOUld be designed by experienced, competent structural engineers employed or engaged by the contractor. A complete structural analysis, including stress diagrams of the structural members must be made to insure satisfactory performance. Due regard should be given to unsymmetrical and eccentric loadings and the fact that the machine must be regularly disassembled as it encounters siphons, bridges, chutes, etc., along the waterway. The large machines are usually hinged so that sections may be passed through or beneath structures. The vertical or lateral deflections, particularly of long-span machines, must be investigated, and sufficient rigidity provided to insure that concrete tolerances will be met. The stability of the machine under the mentioned loading conditions must be fully investigated to insure satisfactory formance. 5.3.2.2.4 -Drawings -The general visions of "Drawings" in Section 1.4 should be met and the contractor should submit drawings of the slipform for review and proval by the engineer-architect. These drawings should show the handling diagrams, the pla'Cing procedure, and the provisions for insuring attainment of the required concrete surfaces. S.4-Permanent forms 5.4.1 -Discussion Permanent forms, as the name implies, are forms left in place that may or may not become an integral part of the tural frame. These forms may be the rigid type such as metal deck, precast concrete, wood, tics, and various types of fiberboard; or the ible type such as reinforced water-repellent rugated paper, or wire mesh with waterproof paper backing. Where the permanent form is used as a deck form it is generally supported from the main structural frame with or without an intermediate system of temporary supports. Page 8 i5 8 Exhibit 28: Fegles Drawing of Jack Bar Layout Plan © 2012. Performance Improvement International Appendix " 15 N <X> '" :c )( LU Xtl'2 l f N 2'4 '"thO",\ t::hpZ. " * ..0, "it, t 1..,,, 0, .<:.afi' ....IQ "'" ."",*.., .0-,.* --w... ,..,,,,crcw"i"Hf' , :;n.,. .,. f .;. ;t.. -;-; ...'" ....." " II , 1 , ....l.jlii..- __
____ . _____._ _3 .," I'A IIII),II Ii\ !. Il i:' ,. "' I' il i I *, ,I " n' I) i I 1 I i .'
<<> N :a :E >< w JI \ \ \ \ \ \ '. I , I """ I /' l '\ \ .' \ .\ ," \ \ \ \ \ ------_.. -------. I ./ I, \. I \. /1'\/ I ' / i I \ .* 11,1 \/ -r t i '" 11 ' 11* *'i \ 'i .I --------.I."!.lIM Exhibit 29: Permeability versus Water Cement Ratio © 2012. Performance Improvement International Appendix 113 "* '*'ml n es t he s i ze , vo/uln e , and continu i t y of c ap ill ar y voids) and maXlmUlI1 'hi c h th e mic r o c ra c k s in th e t r a n s it ion zo n e be/w een the coars, 'I e). P e r meabilit y I Exhibit J igur e 5-2 Influence of water/cement ratio and ma x i m um a gg r eg a te s i z e on concrete permeability
(a) K is a relative measure of the flow of wa t e r t h ro u g h concrete in cubic feet per year per foot of area for a unit hydr a u lic g ra di e nt. [(a), From Concrel uo/, 8th Ed i ti on, U.S. Bureau of Reclamat.i o n, 1 9 75 , p. 3 7) (b), a dap ted from BetonB OR e n , Aa lborg C ement C o., Aalbo r g, Denmark , 19 7 9.] .'meQ/);/ity o f conc rete to water d e p e nd s In a i nly o n t h e rati
140 Max. Aggregate 4-1/2 i1 2 0r 3 i n 1-1/2 in. -100 c: Q) (J -l ao Q) -0 u 1 60 -.tl 14 0 0 Q) E Q) 2 0 ,Q. o l
<"'" 0.4 0.5 0.6 0.7 0 t Woter ICement Rotio (a) 50, 00 0 1 g 20, 0 00L d m o ,=o ' U c E 10,000 ._, '100 Q)33 -II) 0 5,000 a. 5 0 o 30 II) Cl.-Ol 30c 20 III 27 E Q)I/) ...... 24 == Q)O u E, 1,000 1 0 E I u u 500 21 0 t... X 5 = 0 4,8 mm x 0. '0.... u 3 18 0 200 )(....15 Q) u Ce men t 0 100 -'" U P a s te 12 .... 50II) .0 6 o c 20 Q) ::)3 _E I 0 cu _ . . . . Q..(f) 0 0.9 0.4 t Water ICem ent Ra t iO (b) Exhibit 30: Irradiation Effect Appendix VIII-31© 2012. Performance Improvement Exhibit 30 page 1 of 5 NUREG/CR-6927 ORNL/TM-2006/529 Primer on Durability of Nuclear Power Plant Reinforced Concrete Structures -A Review of Pertinent Factors Oak Ridge National Laboratory u.s. Nuclear Regulatory Commission Office of Nuclear Regulatory Research Washington, DC 20555-0001 ____ ..J..... " Exhibit 30 page 2 of 5 Thermal cycling, even at relatively low temperatures (i.e., 65°C), can have deleterious effects on concrete's mechanical properties (i.e., compressive, tensile and bond strengths, and modulus of elasticity are reduced).86 Most reinforced concrete structures are subjected to thermal cycling due to daily temperature fluctuations and are designed accordingly (i.e., inclusion of steel reinforcement). At higher temperatures (200 to 300°C), the first thermal cycle causes the largest percentage of damage, with the extent of damage markedly dependent on aggregate type and is associated with loss of bond between the aggregate and matrix.87 Thermal cycles also can become important if the deformation ofthe structure resulting from the temperature variations is constrained. Additional information on the effects of elevated temperature on concrete materials and structures is available. 88 ,89 lrradiation Irradiation in the form of either fast and thermal neutrons emitted by the reactor core or gamma rays produced as a result of capture of neutrons by members (particularly steel) in contact with concrete can affect the concrete. Changes in the properties of concrete appear to depend primarily on the behavior of the concrete aggregate that can undergo a volume change when exposed to radiation. 90 The fast neutrons are mainly responsible for the considerable growth, caused by atomic displacements, that has been measured in certain aggregate (e.g., flint). Quartz aggregates that contain crystals with covalent bonding should be more affected by radiation than calcareous aggregates that contain crystals with ionic bonding.91 Furthermore, when nuclear radiation is attenuated or absorbed in the concrete almost all the absorbed radiation is converted into heat. Nuclear heating occurs as a result of energy introduced into the concrete as the neutrons or gamma radiation interact with the molecules within the concrete material. The heat generated may have detrimental effects on the physical, mechanical, and nuclear properties of the concrete. Reference 92 indicates that nuclear heating is negligible for incident energy fluxes less than 10 I 0 MeV/cm 2 per s. Determination of whether any deterioration that may occur in concrete properties is due to radiation damage or thermal effects can be difficult. Prolonged exposure of concrete to irradiation can result in decreases in tensile and compressive strengths and modulus of elasticity. Figure 4.7 presents a summary of the effects of neutron radiation on the compressive strength and modulus of elasticity of several concretes. 90 Results in the I iterature 90 indicate that: (I) for some concretes, neutron rad iation of more than I x 10 19 neutrons/cm 2 or 10 10 rads of dose for 14 r 12..!! .Q 1 , 0 "§.. 0,8 '5" 0,6'0 °E 0,4 TO 0 , 2 .. W 5 10 20 2 5 10 21 2 10 18 2 5 10 19 2 5 10 20 2 5 10 21 2 Fluence 01 neutron radiation, nlcm 2 Fluence 01 neutron radiation , nlcm 2 Figure 4.7 Effect of neutron radiation on concrete compressive and modulus of elasticity relative to unirradiated and unheated control specimen Source: H. K. Hilsdorf et aI., The Effects 0/Nuclear Radiation on the Mechanical Properties a/Concrete, ACI SP-55, Douglas McHenry International Symposium on Concrete and Concrete Structures, American Concrete Institute, Farmington Hills, Michigan, 1978. 25 Exh i b i t 30 page 3 o f 5 gamma radiation may cause a reduction in compressive strength; (2) tensile strength of concrete is significantly reduced at neutron fluences exceeding 10 19 nlcm 2 with the decrease of tensile strength caused by neutron radiation more pronounced than the decrease of compressive strength; (3) resistance of concrete to neutron radiation apparently depends on the type of neutrons (slow or fast) involved, but the effect is not clarified; (4) resistance of concrete to neutron radiation depends on mix proportions , type of cement, and type of aggregate; (5) the effect of gamma radiation on concrete's mechanical properties requires clarification; (6) the deterioration of concrete properties associated with a temperature rise resulting from irradiation is relatively minor; (7) coefficients of thermal expansion and conductivity of irradiated concrete differ little from those of temperature-exposed concrete; (8) when exposed to neutron irradiation , the modulus of elasticity of concrete decreases with increasing neutron fluence; (9) creep of concrete is not affected by low-level radiation exposure, but for high levels of exposure creep probably would increase with exposure because of the effects of irradiation on the concrete's tensile and compressive strengths;+ (10) for some concretes, neutron radiation with a fluence of more than I x 10 1 9 neutrons/cm 2 can cause a marked increase in volume; (II) generally, concrete's irradiation resistance increases as the irradiation resistance of the aggregate increases; and (12) irradiation has little effect on shielding properties of concrete beyond moisture loss caused by a temperature increase. Furthermore , there is an indication that nuclear radiation can significantly increase the reactivity of silica-rich aggregates to alkali (i.e., alkali-silica reaction). 102 Results from an investigation of the effect irradiation on the strength of a nuclear power plant concrete indicate that for a dose up to 6 x J 0 5 Gy the compressive, splitting-tensile, and flexural strength of concrete decreased with dose, reaching a reduction of about 10%,5%, and 5%, respectively, at the maximum dose.10 3 It was noted in the reference that interaction of concrete with irradiation generated a succession of chemical reactions starting with radiolysis of water and terminating in formation of calcite crystals that decrease both the size of pore space and the strength of the concrete. Section Ill, Division 2 of the American Society of Mechanical Engineers Pressure Vessel and Piping Code gives an allowable radiation exposure level of lOx 10 20 nvt. 1 04 The British Specification for Prestressed Concrete Pressure Vessels for Nuclear Reactors 105 states that the maximum permissible neutron dose is controlled by the effects of irradiation on concrete properties, and the effects are considered to be insignificant for doses up to 0.5 x JO 18 neutrons/cm 2* Table 2.7 from Ref. 106 provides data for estimated radiation environments at the outside surface of light-water reactor pressure vessels for a 1000 MW(e) plant operating at a capacity factor of80%. These results indicate that radiation levels may approach the limits provided above in a concrete primary shield wall after 40 years of operation (32 equivalent full-power years). However, these values are upper limits and probably higher than would be experienced because of the attenuating effects that would occur due to the presence of air gaps , insulation , etc., that could be positioned between the pressure vessel and concrete structures. More detailed information on the interaction of radiation and concrete is available in Ref. 9) . FatigueNibration Concrete structures subjected to fluctuations in loading, temperature, or moisture content (that are not large enough to cause failure in a single application) can be damaged by fatigue. Fatigue damage initiates as microcracks in the cement paste , proximate to the large aggregate particles, reinforcing steel, or stress risers (e.g., defects). Upon continued or reversed load application, these microcracks may propagate to form structurally significant cracks that can expose the concrete and reinforcing steel to hostile environments or produce increased deflections. Ultimate failure ofa concrete structure in fatigue will occur as a result of excessive cracking, excessive deflections, or brittle fracture. As concrete ages and gains strength, for a given stress level the cycles to failure will increase. [fthe concrete is reinforced or prestressed , properties of the steel tend to control structural performance since + Gamma rays produce radioly s is of water in cement paste that can affect concrete's creep and shrinkage behavior to a limited extent and also resu It in evolution of g a s. 26 Exh i bit 30 page 4 of 5 to that of the yield stress. Other data 186 confirm the effects of temperatures above 200°C on the mild steel reinforcing as well as providing a threshold temperature of about 300°C for loss of bond properties with the concrete. Figure 4.33 presents stress-strain relationships, Young's modulus/elongation, and yield/ultimate strength data as a function of temperature for a 3,500 kgf/cm 2 specified minimum yield strength 51-mm diameter steel bar. 18? Additional information on the effect of elevated temperature on the stress-strain behavior of 12-and 25-mm diameter quenched and tempered steel bars as well as a comparison of results with recommendations provided in the European Code for structural fire design 188 is available. I 89 70 1 2.0 1.5 "5 1.0 '" 0.50 >10 t:::..--------=-------j 0.0 o 15 20 C old , otongu on 0 200 400 600 800 1000 TemperUn. ee) 10 0.0 __-'-_--L_--1-_----' o 200 400 600 800 1000 Temperture eel Figure 4.33 Effect of temperature on properties of a 3,500 kgf/cm 2 minimum specified yield strength steel bar. Source: M. Takeuchi et ai., "Material Properties of Concrete and Steel Bars at Elevated Temperatures," 12'" International Conference on Structural Mechanics in Reactor Technology, Paper H04/4, pp. 13-138, Elsevier Science, North-Holland, Netherlands, 1993. 4.3.2.3 Irradiation Neutron irrad iation prod uces changes in the mechanical properties of carbon steels (e.g., increased yield strength and rise in the ductile-to-brittle transition temperature). The changes result from the displacement of atoms from their normal sites by high-energy neutrons, causing the formation of interstitials and vacancies. A threshold level of neutron fl uence of I x 10 18 neutrons per square centimeter has been cited for alteration of reinforcing steel mechanical properties. 1 90 Fluence levels of this magnitude are not likely to be experienced by the safety-related concrete structures in nuclear power plants, except possi bly in the concrete primary biological shield wall over an extended operating period. I 06 4.3.2.4 Fatigue Fatigue of the mild steel reinforcing system would be coupled with that of the surrounding concrete. The result of appl ied repeated loadings, or vibrations, is generally a loss of bond between the steel reinforcement and concrete. For extreme conditions, the strength of the mild steel reinforcing system may be reduced or failures may occur at applied stress levels less than yield. However, there have been few documented cases of fatigue failures of reinforcing steel in concrete structures and those published occurred at relatively high stress/cycle combinations. 191 Because of the typically low normal stress levels in reinforcing steel elements in nuclear power plant safety-related concrete structures, fatigue failure is not likely to occur. Exhibit page 5 of 5 89. C. R. Cruz, "Elastic Properties of Concrete at High Temperature," Journal Portland Cement H. K. Hilsdorf et a!., The Effects of Nuclear Radiation on the Mechanical Properties of Concrete, ACI SP-55, Douglas McHenry International Symposium on Concrete and Concrete Structures , American Concrete Institute, Detroit , Michigan, 1978. M. F. Kaplan , Concrete Radiation Shielding -Nuclear Physics, Concrete Properties, Design, and Construction, John Wiley & Sons, New York , New York, 1989. American Nuclear Society, Guidelines on the Nuclear Analysis and Design of Concrete Radiation Shieldingfor Nuclear Power Plants, American National Standard, ANSI! ANS-6.4-1985, La Grange Park, Illinois, 1985. S. C. Alexander, " Effects of Irradiation on Concrete: Final Results ," Atomic Energy Research Establishment, Harwell , United Kingdom, 34 pp., 1963. B. T. Price , C. C. Horton, and K. T. Spinney, "Radiation Shielding ," International Series of Monograph on Nuclear Energy, pp. 276-278 , Pergamon Press , London, United Kingdom, 1957. M. R. Elleuch, F. Dubois, and J. Rappenau, "Behavior of Special Shielding Concretes and of Their Constituents Under Neutron Irradiation," Fourth United Nations International Conference on the Peaceful Uses of Atomic Energy, UN sales no.: 72.1X, 7 pp., International Atomic Energy Agency, Vienna, Austria, 1972. 1. A. Houben, "The Irradiation of Mortar Test Specimens," 2 nd Conf e rence on Prestressed Concrete Pressure Vessels and Their Thermal Insulation, pp. 170-183, Commission of European Communities, Brussels, Belgium, 1969. B. Stoces, P. Otopal, V. Juricka, and J. Gabriel, "The Effect of Irradiation on the Mechanical Properties of Concrete," Ceskoslovenska Akademie, Translated from the Czech, Oak Ridge National Laboratory Purchase Order 34B-83481, Letter Release No.: T81, STS No.: 14087, Oak Ridge, Tennessee. A. W. Chisholm-Batten, "Effect of Irradiation on Strength of Concrete," Atomic Energy Research Establishment Research Report AERE R 3332, 13 pp., United Kingdom Atomic Energy Authority , Harwell, 1960. V. B. Dubrovskij, Sh.Sh. Ibragimov, A. Ya. Ladygin, and B. K. Pergamenshckik, "The Effect of Neutron Irradiation on Certain Properties of Refractory Concretes," Atomnaya Energiya 21, pp. 108-112,1966. B. S. Gray, "The Effect of Reactor Radiation on Cements and Concrete," Conference on Prestressed Concrete Pressure Vessels, pp. 17-39, Commission of European Communities, Luxembourg, Belgium, 1972. C. F. Van der Schaaf, "Effect of Irradiation and Heating on the Strength of Mortar and Concrete," 2 nd Conference on Pr e stressed Concrete Pressure Vessels and Their Thermal Insulation, Commission of European Communities, Brussels, Belgium , 1969. T. Ichikawa and H. Koizumi, "Possibility of Radiation-Induced Degradation of Concrete by Alkali-Silica Reaction of Aggregates," Journal on Nuclear Science and Technology 39(8), pp. 880-884, Atomic Energy Society of Japan, Tokyo, August 2002. F. Vodak, K. Trtik , V. Sopko, O. Kapickova, and P. Demo, "Effect ofy-Irradiation on Strength of Concrete for Nuclear Safety-Related Structures," Cement and C o ncrete Research 35, pp. 1551, Elsevier Ltd., 2005. 104American Society of Mechanical Engineers, "Code for Concrete Reactor Vessels and Containments," Section III , Division 2 of ASME Boiler and Pressure Vessel Code, ACI Standard 359, New York, New York , 2005. British Standards Institution, Specification for Prestressed Con c rete Pressur e Vessels for Nuclear Reactors, BS 4975, London, United Kingdom, 1973. Science Applications , Inc., Study of Radiation Dosage to Structural Components in Nuclear Reactors, EPRI NP-152, Electric Power Research Institute, Palo Alto, California, 1977. ACI Committee 215, Considerations for Design of C oncrete Structures Subjected to Fatigue, ACI215R-92, American Concrete Institute, Farmington Hills, Michigan, 1992. 73 Exhibit 31: MF-6, Rebar Detail by Fegles Appendix VIII-32© 2012. Performance Improvement I .'" i , i j :; t: ':i F.* m .", .,. .. L .,. . .... , ., " 1>" * ! ! i' -' o'" .... .,. . .,. .", Exhibit 32: ACI 515 Protective Systems © 2012. Performance Improvement International-AppendixVIII-33 Exhibit 32 page 1 of 7 ACI 515.1 R-79 This document has been a_proved for use by cies of the Department of Defense and for listing in (Revised 1985) the DoD Index of Specifications and Standards. A Guide to the Use of Waterproofing, Protective, and Decorative Barrier for 1 Reported by ACI Committee 5151 Byron 1. Zolin, Chairman Warner K. Babcock Clark R. Gunness Dorothy M. Lawrence Andrew Rossi, Jr. Arthur E. Blackman, Sr. Kenneth A. Heffner Stella L. Marusin Donald L. Schlegel Donald E. Brotherson A. L. Hendricks Charles J. Parise Lawrence E. Schwietz Robert W. Gaul James E. Kubanick Charles O. Pratt The revising committee is listed at the end of the document This Guide updates and expands the scope of the cemberl966 ACI JOURNAL. William H. Kuenning was committee report "Guide for the Protection of chairman when this Guide was published. Albert M. crete Against Chemical Attack by Means of Coatings Levy was chairman from 1974 to 1977 when some of and Other Corrosion Resistant Materials," which the information, found in the chapters on peared in the December 1996 ACI JOURNAL. The proofing Barrier Systems" and "Dampproofing Bar-. vious Guide has been revised and is found in rier Systems," was developed. Chapter 6 of this Guide entitled "Protective Barrier Systems." In addition, there are new chapters on "Waterproofing Barrier Systems," "Dampproofing CONTENTS Barrier Systems/' and "Decorative Barrier Systems." Chapter I-Introduction, page 515.lR-2 A separate chapter on conditioning and surface Ll-General discussion preparation of concrete is included because it is 1.2-The systems concept for barriers vant to all the other chapters. 1.3-Barrier performance difficult to define 1.4-Economic factors for barrier selection This Guide is not to be referenced as a complete 1.5-Inspection during application unit. 1.6-Safety requirements Keywords: abrasive blasting; acid treatment (concrete); acid resistance; Chapter 2-Barrier systems: types and hesion; asphalts; chemical attack; chemical cleaning; coating"; concrete bricks; concretes; detergents; emulsifying agents; epoxy resins; finishes; performance requirements, page 515.1R-3 furan resins; glass fibers; inspection; joint sealers; larex (rubber); IllDrtars 2.1-0efinitions of barrier systems[marerials); paints; phenolic resins; plastics, polymers, and resins; polyesrer 2.2-When waterproofing is used resins; polyurethane resins; pmrective coatings; repairs; sealers; silicates; sulfur; surfactants; remperature; rests; vaporbarriers; waterp:rootmg. Foreword ACI Committee 515 was organized in 1936 and lished a report "Guide for the Protection of Concrete Against Chemical Attack by Means of Coatings and Other Corrosion Resistant Materials," in the De-ACI Committee Reports, Guides. Standard Practices, and taries are intended for guidance in designing, planning, executing, Or inspecting construction, and in preparing specifications. ence to these documents shall not be made in the Project ments. If items found in these documents are desired to be part of the Project Documents. they should be incorporated direcUy into the Project Documents. 23-When dampproofing is used 2.4-When protective barrier systems are used 25-Susceptibility of concrete to attack by chemicals 2.6-When decorative painting barrier systems are used Chapter 3-Concrete conditioning and surface preparation, page SIS.IR-12 3.1 -General requirements 3.2-Repair of surface defects 3.3-Stopping or rerouting of water 3.4-Surface preparation ..,.r,@1986, American Concrere Institute. All rights reserved includ-, ing rights of reproduction and use in any form Or by any means, including' the making of copies by any photo process, or by any electronic or meehan-. ica1 device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval 5rs1ern or device, unless permission in writing is obtained from the proprietors. Exhibit 32 page 2 of 7 515.1R.e MANUAL OF CONCRETE PRACTICE Table 2.5.2-Effect of chemicals on concrete see end of Table 2.5.2 for special notations) Effect *Acetic acid, all Disintegrates slowly concentrations Uquid loss by penetration. May contain acetic acid as impurity (which see) Acid waters (pH of 6.5 Disintegrates slowly. In porous or or less) (a) cracked concrete, attacks steel 'Alcohol See ethyl alcohol, methyl alcohol Alizarin Not harmful 'Almond oil Disintegrates slowly 'Alum See potassium aluminum sulfate Aluminum chloride Disintegrates rapidly. In porous or cracked concrete, attacks steel *Aluminum sulfate Disintegrates. In porous or cracked concrete, attacks steel *Ammonia, liquid Ammonia vapors Harmful only if it contains harmful ammonium salts (see below) May disintegrate moist concrete slowly or attack steel in porous or cracked moist concrete Ammonium bisulfate Disintegrates. In porous or cracked concrete, attacks steel Ammonium carbonate Not harmful *Ammonium chloride Disintegrates slowly. In porous or cracked concrete, attacks steel Ammonium cyanide Disintegrates slowly Ammonium fluoride Disintegrates slowly Ammonium hydroxide Not harmful Ammonium nitrate Disintegrates. In porous or cracked concrete, attacks steel Ammonium Not harmful 'Ammonium sulfate Disintegrates. In porous or cracked concrete, attacks steel Ammonium sulfide Disintegrates Carbazole Carbolic acid 'Carbon dioxide *Carbon disulfide "Carbon tetrachloride 'Carbonic acid sulfate resistance Not harmful See phenol Gas may cause permanent shrinkage (see also carbonic acid) May disintegr ate slowly Uquid loss by penetration of concrete Disintegrates slowly (c) Ammonium sulfite Disintegrates Ammonium superphosphate Disinteg rates. In porous or cracked concrete, attacks steel Ammonium thiosulfate Disintegrates Animal wastes See slaughter house wastes Anthracene Not harmful Arsenious acid Not harmful Effect Ashes Harmful if wet, when sulfides and sulfates leach out (see sodium sulfate) Ashes, hot Cause thermal expansion Automobile and diesel May disintegrate moist concrete by exhaust gases (n) action of carbonic, nitric, or sulfurous acid 'Baking soda See sodium bicarbonate Barium hydroxide Not harmful See tanning bark *Beef fat Solid fat disintegrates slowly, melted fat more rapidly May contain, as fermentation products, acetic, carbonic, lactic, or tannic acids (which see) Benzol (benzene] Uquid loss by penetration Bleaching See specific chemlcal, such as hypochlorous acid, sodium hypochlorite, sulfurous acid, etc. 'Borax Not harmful *Boric acid Negligible effect 'Brine See sodium chloride or other salt Gaseous bromine disintegrates. Uquid bromine disintegrates if it contains hydrobromiC acid and moisture *Buttermilk Disintegrates slowly Butyl stearate Disintegrates slowly Calcium bisulfite Disintegrates rapidly "Calcium In porous or cracked concrete, attacks steel. (b) Steel corrosion may cause concrete to spall 'Calcium hydroxide Not harmful Calcium nitrate Not harmful 'Calcium sulfate Disintegrates concrete of inadequate Exhibit 32 page 3 of 7 SURFACE BARRIER SYSTEMS 515.1R*7 Table 2.5.2-(Continued) Material Effect Castor oil Disintegrates, especially in presence of air Chile saltpeter See sodium nitrate China wood oil Liquid disintegrates slowly. Chlorine gas Slowly disintegrates moist concrete Chrome plating solutions (0) Disintegrates slowly Chromic add, all concentrations Attacks steel in porous or cracked concrete Chrysen Not harmful *Cider DiSintegrates slowly (see acetic add] Cinders Harmful if wet, when suHides and sulfates leach out (see, for example, sodium sulfate) Cinders, hot Causethermalexpanmon Coal Sulfides leaching from damp coal may oxidize to sulfurous or sulfuric add, or ferrous sulfate (which see) Coal tar oils See anthracene, benzol, carbazole, chrySen, creosote, cresol, cumo!, paraffin, phenanthrene, phenol, toluoL xylol Cobalt sulfate Disintegrates concrete of inadequate sulfate resistance 'Cocoa bean oil Disintegrates, especially in presence of air 'Cocoa butter Disintegrates, especially in presence of air Coconut oil Disintegrates, especially in presence of air 'Cod liver oil Disintegrates slowly Coke Sulfides leaching from damp coke may oxidize to sulfurous or sulfuric acid (which see] Copper chloride Disintegrates slowly Copper plating solutions (P) Not harmful Copper sulfate Disintegrates concrete of inadequate sulfate resistance Copper sulfide Harmful if it contains copper sulfate (which see) 'Com syrup Disintegrates slowly Corrosive sublimate See mercuric chloride Material Effect *Cottonseed oil Disintegrates, especially in presence of air Creosote Phenol present disintegrates slowly Cresol Phenol present disintegrates slowly Cumol Liquid loss by penetration Delcing salts Scaling of non-air-entrained or insufficiently aged concrete (b) Diesel gases See automobile and diesel exhaust gases Dinitrophenol Disintegrates slowly Dis tiller's slop Lactic acid causes slow disintegration Epsom salt See magnesium sulfate *Ethyl alcohol Liquid loss by penetration "Ethyl ether Liquid loss by penetration "Ethylene glycol Disintegrates slowly (d) Feces See manure "Fermenting fruits, grains, vegetables, or extracts Industrial fermentation processes produce lactic acid. (e) Disintegrates slowly (see lactic add) Ferric chloride Disintegrates slowly Ferric nitrate Not harmful Ferric sulfate Disintegrates concrete of inadequate quality Ferric sulfide Harmful if it contains ferric sulfate (which see) Ferrous chloride Disintegrates slowly Ferrous sulfate Disintegrates concrete of inadequate sulfate resistance Fertilizer See ammonium sulfate, ammonium superphosphate, manure, potassium, nitrate, sodium nitrate Fish liquor Disintegrates (I) *Fish oil Disintegrates slowly Flue gases Hot gases (400-11 0 0 F) cause Ihermal stresses. Cooled, condensed sulfurous, hydrochloric acids disintegrate slowly Foot oil Disintegrates slowly 'Formaldehyde, 37 percent Formic add, formed in solution, disintegrates slowly Formalin See formaldehyde Exhibit 32 page 4 of 7 515.1R-8 MANUAL OF CONCRETE PRACTICE Table 2.5.2-(Continued) Effect 'Fonnie acid, Disintegrates slowly percent 'Formic acid, 30 Disintegrates slowly percent 'Formic acid, Disintegrates slowly percent 'Fruit HydroflUoric, other adds, and sugar cause disintegration (see also fermenting fruits, grains, vegetables, extracts) Gas water (g) Ammonium salts seldom present in sufficient quanti!), to disintegrate Gasoline Liquid loss by penetration 'Glucose Disintegrates slowly 'Glycerine Disintegrates slowly 'Grain See fermenting fruits, grains, vegetables, extracts 'Honey Not harmful Horse fat Solid fat disintegrates slowly, melted fat more rapidly Humic Disintegrates slowly 'Hydrochloric acid, Disintegrates rapidly, including steel concentrations Hydrofluoric acid, all Disintegrates rapidly, including steel concentrations Hydrogen Not harmful dry. In moist, oxidizing environments converts to sulfurous acid and disintegrates slowly Hypochlorous acid, Disintegrates slowly percent Disintegrates slowly Liquid loss by penetration of concrete 'Lactic acid, Disintegrates slowly percent 'Lamb fat Solid fat disintegrates slowly, melted fat more rapidly 'Lard and lard oil lard disintegrates slow ly, lard oil more rapidly Lead nitrate Disintegrates slowly Lead refining solutions Disintegrates slowly (q) saltpeter See ammonium nitrate and ammonium sulfate Material Effect Lignite oils If fato/ oils are present, disintegrates slowly 'Linseed oils Liquid disintegrates slowly. Dried or drying films are harmless Locomotive gases (r) May disintegrate moist concrete by action of carbonic, nitric or sulfurous acids (see also automobile and diesel exhaust gases) Lubricating oil Fato/ oils, if present, disintegrate slowly Lye See sodium hydroxide Machine oil Fato/ oils, if present, disintegrate slowly 'Magnesium chloride Disintegrates slowly. In porous or cracked concrete, attacks steel Magnesium nitrate Disintegrates slowly 'Magnesium sulfate Disintegrates concrete of inadequate sulfate resistance Manganese sulfate Disintegrates concrete of inadequate sulfate resistance Manure Disintegrates slow ly 'Margarine Solid margarine disintegrates slowly, melted margarine more rapidly Mash, fermenting Acetic and lactic acids, and sugar disintegrate slowly Mercuric chloride Disintegrates slowly Mercurous chloride Disintegrates slowly Methyl alcohol Liquid loss by penetration Methyl ethyl ketone Liquid loss by penetration Methyl isobutyl ketone Liquid loss by penetration 'Milk Not harmful. However, see sour milk Mine water, waste Sulfides, sulfates, or adds present disintegrate concrete and attack steel in porous-or cracked concrete 'Mineral oil Fato/ oils, if present, disintegrate slowly Mineral spirits Liquid loss by penetration 'Molasses At temperatures ..120 F, disintegrates slowly Muriatic acid See hydrochloric acid 'Mustard oil Disintegrates, especially in presence of air Nickel plating solutions (v) Nickel ammonium sulfate disintegrates slowly Exhibit 32 page 5 of7 SURFACE BARRIER SYSTEMS 515.1R*9 Table 2.5.2-(Continued) Material Effect Nickel sullate Disintegrates concrete of inadequate sulfate resistance Niter See potassium nitrate Nitric acid, all concentrations Disintegrates rapidly "Oleic acid, 100 percent Not harmful Oleum See sulfuric add, 110 percent "Olive oil Disintegrates slowly Ores Sulfides leaching from damp ores may oxidize to sulfuric acid or ferrous sulfate (which see) Oxalic add Not harmful. Protects tanks against acetic acid, carbon dioxide, salt water. Poisonous. Do not use with food or drinking water Paraffin Shallow penetration not harmful, but should not be used on highly porous surfaces like concrete masonry (u) 'Peanut oil Disintegrates slowly Perchloric acid, 10 percent Disintegrates Perchloroethylene Liquid loss by penetration Petroleum oils Liquid loss by penetration. Fatty oils, if present, disintegrate slowly Phenanthrene Liquid loss by penetration Phenol, 5*25 percent Disintegrates slowly 'Phosphoric acid, 10-85 percent Disintegrates slowly 'Pickling brine Attacks steel in porous or cracked concrete Pitch Not harmful 'Poppy seed oil Disintegrates slowly 'Potassium aluminum sulfate Disintegrates concrete of inadequate sulfate resistance "Potassium carbonate Harmless unless potassium sulfate present (which see) "Potassium chloride Magnesium chloride, if present, attacks steel in porous or cracked concrete Potassium cyanide Disintegrates slowly Potassium dichromate Disintegrates Potassium hydroxide, 15 percent Not harmful (h) Material Effect Potassium hydroxide, 25 percent or over Disintegrates concrete 'Potassium nitrate Disintegrates slowly Potassium permanganate Harmless unless potassium sulfate present (which see) Potassium persulfate Disintegrates concrete of inadequate sulfate resistance Potassium sullate Disintegrates concrete of inadequate sulfate resistance Potassium sulfide Harmless unless potassium sulfate present (which see) Pyrites See ferric sulfide, copper sulfide "Rapeseed oil Disintegrates, especially in presence of air Rock salt See sodium chloride Rosin Not harmful Rosin oil Not harmful Sal ammoniac See ammonium chloride Sal soda See sodium carbonate Salt for deicing roads See text. Also calcium chloride, magnesium chloride, sodium chloride Saltpeter See potassium nitrate "Sauerkraut Flavor impaired by concrete. Lactic acid may disintegrate slowly Sea water Disintegrates concrete of inadequate sulfate resistance. Attacks steel in porous or cracked concrete Sewage Usually not harmful (see hydrogen sulfide] Silage Acetic, butyric, lactic acids (and sometimes fermenting agents of hydrochloric or sulfuric adds) disintegrate slowly Slaughter house wastes (w) Organic acids disintegrate Sludge See sewage, hydrogen sulfide Soda water See carbonic acid *Sodium bicarbonate Not harmful Sodium bisulfate Disintegrates Sodium bisulfite Disintegrates Sodium bromide Disintegrates slowly Exhibit page 6 of7 MANUAL OF CONCRETE PRACTICE Table 2.5.2-(Continued) Effect Sodium carbonate Not harmful, except to calcium aluminate cement "Sodium Magnesium chloride, if present, attacks steel in porous or cracked concrete. (b) Steel corrosion may cause concrete to spall Sodium cyanide Disintegrates slowly Sodium dichromate Dilute solutions disintegrate slowly "Sodium hydroxIde, Not harmful (h) 1-10 percent "Sodium hydroxide, Disintegrates concrete 20 percent or over Sodium hypochlorite Disintegrates slowly "Sodium nitrate Disintegrates slowly Sodium nitrite Disintegrates slowly Sodium phosphate Disintegrates slowly (monobasic) Sodium sulfate "Sour milk Disinte grates concrete of inadequate sulfate resistance Lactic acid disintegrates slowly Effect Sulfurous acid Disintegrates rapidly Tallow and tallow oil Disintegrates slowly Tannic acid Disintegrates slowly Tanning bark May disintegrate slowly if damp (see tanning liquor) Tanning liquor Disintegrates, if acid 'Tartaric acid solution Not harmful Tobacco Organic acids, if present, disintegrate slowly Toluol (toluene) liquid loss by penetration 'Trichloroethylene Liquid loss by penetration 'Trisodium phosphate Not harmful Tung oil liquid disintegrates slowly. Dried or drying films are harmless Turpentine Mild attack. liquid loss by penetration 'Urea Not harmful Urine Attacks steel in porous or cracked concrete Vegetables See fermenting fruits, grains, vegetables, extracts Vinegar Disintegrates slowly (see acetic acid) Walnut oil Disintegrates slowly 'Whey Disintegrates slowly (see lactic acid) Sodium sulfide "Sodium sulfite Sodium thiosulfate Disintegrates slowly Sodium sulfate, if present, disintegr ates concrete of inadeq uate sulfate resistance Slowly disintegr ates concrete of inadequate sulfate resistance 'Wine Not harmful. Necessary to prevent "Soybean oil Liquid disintegrates slowly. Dried or drying films harmless Wood pulp Xylol (xylene) 'Zinc chloride Zinc nitrate Zinc refining solutions flavor contamination Not harmful liquid loss by penetration Disintegrates slowly Not harmful Hydr ochloric or sulfuric acids, if Strontium chloride Not harmful *Sugar Disintegrates slowly Sulfite liquor Disintegrates Sulfite solution See calcium bisulfite
Sulfur dioxide With moisture forms sulfurous acid (which see) (x) Zinc slag present, disintegrate concrete Zinc sulfate (which see) sometimes*Sulfuric acid, 10-80 Disintegrates rapidly percent Zinc sulfate formed by oxidation Disintegrates slowly *Sulfuric acid, 80 percent oleum Disintegrates v x Exhibit 32 page 7 of 7 SURFACE BARRIER SYSTEMS 515.1R-11 Key to special notations-Table 2.5.2

Sometimes used in food processing or as food or beverage ingredient.
Ask for advisory opinion of Food and Drug Administration regarding coatings for use with food ingredients. a Waters of pH higher than 6.5 may be aggressive if they also contain bicarbonates. (Natural waters are usually of pH higher than 7.0 and seldom lower than 6.0, though pH values as low as 0.4 have been reported. For pH values below 3, protect as for dilute acid.) b Frequently used as a deicer for concrete pavements. If the concrete contains too little entrained air or has not been aged more than one month, repeated application may cause surlace scaling. For protection under these conditions, see "deicing salts." Carbon dioxide dissolves in natuml waters to form carbonic acid solutions. When it dissolves to extent of 0.9 to 3 parts per million it is destructive to concrete. d Frequently used as deicer for airplanes. Heavy spillage on runway pavements containing too little entrained air may cause surface scaling. e In addition to the intentional fermentation of many raw materials, much unwanted fermentation occurs in the spoiling of foods and food wastes, also producing lactic acid. Contains carbonic acid, fish oils, hydrogen sulfide, methyl amine, brine, other potentially reactive materials. g Water used for cleaning coal gas. h However, in those limited areas of the United States where concrete is made with reactive aggregates, disruptive expansion may be produced. Composed mostly of nitrogen, oxygen, carbon dioxide, carbon monoxide, and water vapor. Also contains unburned hydrocarbons, partially burned hydrocarbons, oxides of nitrogen, and oxides of sulfur. Nitrogen dioxide and oxygen in sunlight may produce ozone, which reacts with some of the organics to produce formaldehyde, peracylnitmtes, and other products. o These either contain chromium trioxide and a small amount of sulfate, or ammonium chromic sulfate [nearly saturated) and sodium sulfate. p Many types of solutions are used, including (a) Sulfate-Contain copper sulfate and sulfuric acid. (b) Cyanide-Contain copper and sodium cyanides and sodium carbonate. (c) Rochelle-Contain these cyanides, sodium carbonate, and potassium sodium tartrnte. (d) Others such as fluoborate, pyrophosphate, amine, or potassium cyanide. q Contains lead fluosilicates and fluosilicic acid. Reference here is to combustion of coal, which produces carbon dioxide, water vapor, nitrogen, hydrogen, carbon monoxide, hydrates, ammonia, nitric acid, sulfur dioxide, hydrogen sulfide, soot, and ashes. u Porous concrete which has absorbed considerable molten paraffin and then been immersed in water after the paraffin has solidified has been known to disintegrate from 90rptive forces. Contains nickelous chloride, nickelous sulfate, boric acid, and ammonium ion. w May contain various mixtures of blood, fats and oils, bile and other digestive juices, partially digested vegetable matter, urine, and manure, with varying amounts of water. Usually contains zinc sulfate in sulfuric acid. Sulfuric acid concentration may be low (about 6 percent in "low current density" process) or higher (about 22-28 percent in "high current density" process). Exhibit 33: Corrosion Related Photos © 2012. Performance Improvement International-Appendix Page 1 of 3 'l." -IJl--..f.+-,- ...
Exhibit 34: Concrete Mix Summary for Below Grade Appendix VIII-35© 2012. Performance Improvement Exhibit 34 5.65 3384 9120 3522 5556 207.6 1727.232 0.51 5.5% 5.50 31 5.15 3384 9030 3642 5400 185.4 1542.528 0.46 4.5% 6.00 31 5.32 3348 9000 3570 5646 190.2 1582.464 0.47 5.0"10 3.75 37 Field cast 5.46 3384 8940 3678 5340 196.2 1632.384 0.48 4.5% 4.00 38 6.34 3102 8700 4080 5970 184.8 1537.536 0.50 4.5% 4.00 24 5.77 3384 9108 3480 5640 207.6 1727.232 0.51 3.5% 4.50 5 15:32 5.95 3384 9270 3300 5496 214.2 1782.144 0.53 6.0"/0 5.75 9 2138 5.93 3384 9270 3480 5292 213.6 1777.152 0.53 5.2% 5.75 0 3:42 5.63 3384 9156 3480 5460 207 1722.24 0.51 4.5% 5.50 -2 1230 5.90 3384 9000 3690 5460 212.4 1767.168 0.52 5.5% 6.00 12 21:12 5.96 3384 8940 3540 5610 213.6 1777.152 0.53 4.5"10 6.50 16 248 5.96 3384 8940 3564 5610 213.6 1777.152 0.53 4.8% 6.00 19 9:13 5.86 3384 8940 3660 5610 210.6 1752.192 0.52 6.0"10 6.00 22 14:29 5.64 3384 9000 3876 5280 202.8 1687.296 0.50 5.5% 5.00 29 21:02 5.72 3384 8940 3570 5010 205.8 1712.256 0.51 5.5% 5.50 28 341 5.57 3384 9000 3540 5010 200.4 1667.328 0.49 6.0"/0 4.50 32 11:17 6.02 3384 8550 3690 5436 217.2 1807.104 0.53 6.5% 5.00 34 1833 5.78 3384 8724 3684 5496 207.6 1727.232 0.51 4.5% 5.50 36 Average: 0.51 5.1% 5.26 SID: 0.02 0.8% 0.81 Count: 18 18 18 Concrete mix summary for belowijrade concrete -Mix C-2-SF-2 with Type II cement Page 1 of 1 Exhibit 35: Concrete Strength Summary for Below Grade Appendix VIII-36© 2012. Performance Improvement 7 days 3661 3236 3395 3059 3625 3059 3059 3908 3342 3059 3360 3289 3378 3148 3272 3218 3059 28 days
28 days 90 90 days Average: SID: 7 days
Concrete Strength summary for below-grade concrete -Mix C-2-SF-2 with Type II cement 28 90 Exhibit 35 Page l of Exhibit 36: Concrete Strength Summary for Above Grade © 2012. Performance Improvement International-Appendix Exhibit 36 4881 4615 4587 6136 6172 7491 7352 4601 6154 7422 4442 4562 6085 6083 7003 7576 4502 6084 7290 4032 4386 5871 5853 6844 6861 4209 5862 6853 4739 4828 6649 6207 7463 7109 4784 6428 7286 4669 4880 5924 6136 7427 7356 4775 6030 7392 4810 4775 6070 5942 7074 7162 4793 6006 7118 .4810 4825 5517 5606 7250 6791 4818 5562 7021 5040 4916 5553 5234 6285 6720 4978 5394 6503 4067 4191 5126 4881' 5896 5871 4129 5004 5884 4474 4315 5234 5553 6826 6879 4395 5394 6853 4297 4330 5483 5853 6667 7144 4314 5668 6906 4633 4669 6154 6366 7374 7639 4651 6260 7507 5146 5181 5641 5942 7639 7392 5164 5792 7516 5199 5111 6702 5765 7445 7728 5155 6234 7587 4916 4916 6225 6313 7498 7958 4916 6269 7728 4651 4580 6154 6260 7887 7421 4616 6207 7654 4315 4421 6154 5959 6720 6861 4368 6057 6791 4757 4434 5234 5270 7356 7162 4596 5252 7259 3837 3926 4704 4757 7162 6738 3882 4731 6950 4633 4704 5712 5747 7816 7993 4669 5730 7905 4562 4669 6348 5836 7816 7710 4616 6092 7763 4492 4403 5500 5836 6867 7639 4448 5668 7253 4315 4262 5765 5730 7162 6649 4289 5748 6906 4279 4563 5447 5959 7569 7463 4421 5703 7516 4244 4069 5730 5482 7056 7215 4157 5606 7136 4456 4368 5464 5553 6967 7003 4412 5509 6985 4969 4645 5977 5485 7374 7604 4807 5731 7489 5252 5093 6543 6366 7816 8099 5173 6455 7958 4633 4474 5818 6030 7250 7569 4554 5924 7410 4050 3802 5199 5164 6508 6684 3926 5182 6596 4403 4244 5058 5252 6832 7180 4324 5155 7006 4633 4633 5800 5659 7233 7569 4633 5730 7401 4545 4633 6083 6030 7463 7710 4589 6057 7587 4368 4323 5659 6295 6967 7003 4346 5977 6985 4226 5641 5341 7710 7321 4226 5491 7516 4526 4244 5588 5439 7250 7091 4385 5514 7171 4156 4209 5508 5500 7063 6614 4183 5504 6839 4103 4138 5270 5694 6561 6578 4121 5482 6570 3714 3754 5376 5120 6225 6295 3734 5248 6260 4709 4612 6172 6437 7533 7427 4661 6305 7480 4562 4598 6541 6360 7215 7003 4580 6451 7109 4244 4244 5863 5059 6738 7109 4244 5461 6924 4350 4350 4225 5800 6355 6508 4350 5013 6432 3873 3969 4810 5199 6245 6295 3921 5005 6270 4491 4403 5411 5022 6619 6295 4447 5217 6457 4032 4191 5677 5677 6667 6614 4112 5677 6641 4315 4598 5889 6278 7922 7710 4457 6084 7816 4297 4226 6860 5800 7675 8135 4262 6330 7905 3908 3714 5906 5818 7533 7374 3811 5862 7454 4180 4156 6043 5617 7034 6985 4168 5830 7010 4478 4598 6109 5836 7356 6890 4538 5973 7123 4375 4173 5487 5588 7567 7394 4274 5538 7481 3696 3714 5906 6119 7763 7874 3705 6013 7819 3376 3466 5401 5783 7409 7576 3421 5592 7493 4562 4492 6824 6242 8001 8192 4527 6533 8097 4334 4278 5694 5765 7410 7657 4306 5730 7534 3943 3908 6066 5800 7269 6718 3926 5933 6994 3784 3655 5553 5482 7749 7927 3720 5518 7838 4527 4527 6331 6500 7985 7995 4527 6416 7990 Page 1 of 2 Exhibit 36 4474 6154 71 3714 4226 5765 5783 6739 7180 3970 5774 6960 4810 4589 6525 6172 7675 8028 4700 6349 7852 4315 4297 6419 6030 7692 7675 4306 6225 7684 3760 3749 5906 5698 6423 6808 3755 5802 6616 4032 4050 5500 5517 6702 6861 4041 5509 6782 3979 3678 5747 5765 6455 6684 3829 5756 6570 3767 3661 5783 5219 6596 6773 3714 5501 6685 3466 3943 5623 5600 6826 6932 3705 5612 6879 3289 3590 5959 5765 7569 7889 3440 5862 7729 3431 3448 4987 5447 6437 6331 3440 5217 6384 2812 2812 5111 4845 6455 6561 2812 4978 6508 3979 3784 5181 5500 6260 6189 3882 5341 6225 Average: 4100 5749 7079 StD: 582 400 505 Count: 92 92 91 Max: 5173 6533 8097 Min: 2812 4731 5884 Concrete Strength summary for above-grade concrete -Mix C-2-SF-2 (5/4f71 to 5 1 6/71) and C-2-SF-4 w i th Type I cement Page 2 of 2 Exhibit 37: Earthquake Event © 2012. Performance Improvement International-Appendix Davis-Besse Classifiable Events Page lof2 Exhibit 37 Page 1 of 10 Davis-Besse Classifiable A total of 34 declared emergencies/classlflable events have occurred at Davis-Besse. Of these events there have been 4 Alerts and 30 Unusual Events. Several of the pre-1993 events are not currently classifiable under our current EALs due to the NRC allowing the elimination of the Technical Specification
3.0.3 Unusual
Event EAL and several others EALs that were administrative situations and not actuaJ emergency events in 1993. Event classifications are linked to the NRC Dail3l Event Reoort where applicable
CLASSIFICAIION EVENTAlert Due to Fire in Electrical Bus Affecting 11/16/11 Alert Safety Related Equipment Unusual Event Due to a Fire and Explosions in 01119/11 Unusual Event the Protected Area Transitory Alert due to catastrophic failure of Alert 06/25/09 ccpn in Switchyard of offsite power caused by grid OR/14101 UnusualEvent II. 1 ll.l<:!,U\'oCI Loss of offsite power caused by outage 04/23100 Unusual Event electrical system testing Misc. -Downgrade from Alert 06/26/98 Unusual Event Alert Tornado striking the facility Both Control Room ventilation systems were 06124198 12/22/93 declared inoperable due to a small refrigerant leak Chlorine gas release in Water Treatment Unusual Event 10/08/90:
UnusullLEvellt Building Unplanned ECeS actuation during outage 05/18/90 Unusual Evel)t testing 02/09/89 Low Lake Level Transportation to an off site medical facility of Unusual Event 04/06188 Unysuill a potentially contaminated injured individual Loss of Decay Heat Removal System (Cooler 03/04/88 Alert inlet valves declared inoperable) http://dbweb/LicenseiDocumentslNRCIDERIClassEvents.htm 111412012 Davis-Besse Classifiable Events Page 2 of2 Exhibit 37 Page 2 of 01101188 Low Lake Level 12115/87 Unusual Low Lake Level 03/30/87 Unusual Event SFAS Sequencer out of tolerance (T.S. 3.0.3) 01112/87 Unusual Event Auxiliary Feedwater pressure switches out of .1 IT C'l ., £\ ", 03/05/86 Unusual Event::E Activity 1'" lVfO,", .L,yvlJ I J../VW J....vvvl 06/09/85 UnusYill Event Loss of Main Feedwater/Auxiliary Feedwater Malfunction 05116/85 Unusual Event ReS Leak (Pressurizer Spray Value Packing Leak) 05106/85 Unusual Event Loss of Meteorological Indications 05102/84 Unusual Event Loss of Meteorological Indications 03/02/84 Unusual Event Main Steam Line Safety Valve Stuck Open 02/21184 Unusual Event Loss of Meteorological Indications 01117/84 Unusual Event Loss of Meteorological Indications 12/17/83 Unusual Event RCS Leak (Letdown System Packing Leak) 01118183 Unusual Event Loss of Containment Integrity (No.2 Main Steam Safety Leaking) 1 12116/82 Unusual Event Overturned Gasoline Truck east ofDBAB on SR 2 under transmission lines 19/81 Unusual Event Loss of Meteorological Indications 02/04/81 Unusual of Meteorological Indications 07/29/80 Unusual Event Eye Injury Non-Nuclear Related 06125180 Unusual Event S in Control Room 04/13/80 Unusual Event Flood Watch Return to Other Licensing Documents http://dbweblLicense/DocumentsINRCIDERlClassEvents.htm ,

Page 1 ofl Exhibit Page 3 of

+-----------------------+ IPOWER IEVENT NUMBER: 3837 +-----------------------+ [FACILITY: DAVIS BESSE REGION: 3 INOTIFICATION DATE: [UNIT: (1) [ J [ ) STATE: OH INOTIFICATION TIME: IRX TYPE: (1] B&W-R-LP IEVENT DATE: 03/05/86 +------------------------------------------------+EVENT TIME: 08:07 [EDTJ I I NRC NOTIFIED I LAST UPDATE DATE: IHQ OPS +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS IEMERGENCY +-----------------------------+ 110 CFR SECTION: I CREED RIll I I ALLISON EO I I GREINER FEMA I I +-----+----------+-------+----- lUNIT !SCRAM CODE/RX CRITIINIT PWRI INIT RX MODE lCURR PWRI CURR RX MODE ) I 1 INN 0 COLD SHUTDOWN I 0 COLD SHUTDOWN I I I +--- EVENT TEXT UNIT IN COLD SHUTDOWN -AT 0807 EST STATION SEISMIC MONITOR iZT2957 INDICATED A SEISMIC EVENT ON SITE. AT 0845 EST LICENSEE DECLARED AN UE. NO PHYSICAL MOVEMENT AT THE SITE WAS OBSERVED. LICENSEE CONTACTED FERMI AND PERRY SITES AND THERE WAS NO SEISMIC INDICATION AT EITHER SITE. LICENSEE SUSPECTED THAT THE INDICATION WAS SPURIOUS. RI WILL BE *
UPDATE *

AT 1034 LICENSEE TERMINATED UE. NOTIFIED R3 CREED, EO FEMA .-----------+
http://dbweb/Licenseillocuments/NRC/DERl03837.txt 1114/2012 .. / q'2 6. Page 4 of 1,1.,lO;,..,. ,-..""--,,-, I ! " I v I',. I " ... POWEll ST. \ of to ... ION REPORt t------.. "'Mcl> ad(hl'U'l<J1 _.4. ..rn 1 ,,( 0"(">'" @P.,... V""'if I&J f ... $1 UEFEfI"NCf 0 d -------------------_. yJllf TlO"W'$"H'IAI. IliSlI'vt'lIO,'OS o VI', ..cl.a, n AHI.\O vr.l'II..d .... ' CJ O,,4Iitv A."**:a.t,,, '0 D T 11Ilnln\l SUPlI..".ur , . .......*... t Exhibit 37 IVan' D£SCltlP'rICNt 7(.J)J<", /Ie /-*. t ) "I. Ill>; 11"'('t!ili .. / cIa .. l.ott I<=I"-.e,,( (I If c if;""" cot* (,; .1' {c. f ,,"(:1 r t'd q A E
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A',.* 4 (4,',..,;' . L( rl-.'t',-( ( <", ... v-rA. n 1/1 J'j/r e\ &t,,Ir, a "I ,.f "<" c1 'I y ft* 6* s 0I1:S (' I"/' t I. rle ..:f -flu. S'e;sh,,'C <ht:tt......rl( "('1 {,-:. <# ..,1 ... {fA." ))t":( t'.( I ill (fit) 4 . ( ....:.... ...* ..:.:.. ; ...., .
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!:"t'i"'r J 1-'(/II1}1 1-(';, rn .. f I {I -,1 'f jJ<'r e"j /-v""7' ;l.' K t..:ff!." I it' Ir(; l / I, ,.., -f" ,'1 (.' / t' '] fi i i..'I!.. s , >11'*1, -I ;1 l' I, 1,:'/ (1-'" liJtl r. .... :, . Exhibit 37 Page 7 of 10 , eau.,. 0' Atb il'ld kltll".0.,""111 of o.oIop Marctt 10, 1986 (411) JU*24lQf ..... lUtts Storz, Plant Manlger .., Tol",i'f\ Edison COIIIpIR¥ _ lthtdtson M.S. 12103 Ohio 43652 0:..,,. Mr. Storz: Tftis lG-tter is to conf1... my oral conversation of March 5, 1986, during."tc:1q ] stated that 00 unusual sehlie "tid\;' occurred 1n the Toledo between 8:00 A.M. and 9:00 A.M., Eastern Standard Time (13:00 t\>\"¥.;f.lgh 14:00 Universal Time). of that date. Our instrumentation d'Fr-,il$ one short-period vertical which has been and continues to detect lIIOderate to large telese1sms as well as local quarry blasts and cultural noise. The only vibrations detected by this transducer, located,in the basement of Bowman-Oddy Laboratoriel on the University of Toledo campus. during the time in question were the vibrations aSSOCiated with traffic or other human activities nearby. I thus that the instrument was working properly and that that could be termed an "earthquaketl,occurred in the ToledO area. , J " Vibr.Uons frOll thE: Chardon, Ohio' earthquake of January 31, on the other hind,wer. S(} strong that our record was clipped (the dynamic range of the slst-was exceeded). / Sllt;frel Y , Donald J. 'it"te,..n Assistant Professor of Geology DJS/b .. ... ". ., IIll[ IfCtrIIt 1.1 OIlflS I Ul D I ., ()1tAf1'l 10 A _H..!: * "l :..,"1..- Mi... x IJ:IJ.R . ................ ---;-:.::J.:-..... .. _......+---" --it-x -"!: .-......-. r-- =-
----j r.LM .
I , ec, .! I .;.4" . .1i:lc:C I .. ..* StC't' (: ) fitl' ....,1 COMMENTS: I , 10 (}r/(l ) oI:t fa. tV'*'p . : /' '" . ' -----.. ______________________

.... ....______RIVII!W C:OJ\lOUCTEO IV O......II...'IOM C"II ..... *..OIVIOUAI. l) W. t>1L\ \)*:,.J O ... "ISPONN TO ....CH CO..."""" 'I "iQU.ITIO. "1.1"'11 "ITUAN THII '0"'" WITH YOUI'I "'II'ONIIIN TH"' .AC. 'AOVIOED, ' ......:.. tlftt' () I/Il ;" 0 ..------.... ... .. ....______COMMIHTI AISPONSI
.; " I! (.4,......1 7....#I-l-. b H /I 4 h H 11..' (!C A -'1-f-/ z J, .../t..,"'. ()II /lI-ftL ' . ) ) J 2.111 , .' ()1.-I..N I-Vi !M' .. 1_.........
Sl>p <15"0 J "E 9" (w...k 1-3)j YVA-r-X va, R§C IN .....-.0.\ " Ub'A IN 4 l P j £bC, 11* I-!; [be; (-'l. "".. 1),,) ., ( .-1., '. c>j /0 .."'t....:+/-lr L r.L\.'rd N f s,. M ... a.."d ;"4-;..-& i .... ". 1100 .. h 1f..J.. ti.¥ :vJA;p' hm HI/V 7/u....... -tL. (:4>>\ {+vi In 1"1 e 1'11/, 0, s t:1u.. 44\ ." ,. n.n. t U i II 3 P .sL f I.--. t1. M 4 ok. A .1-1 e?fL....., A ,,-I '"' x' 14 ,ia.. fY-* 1>/1(4& Exhibit 38: Shrinkage Crack Photos Appendix VIII-39© 2012. Performance Improvement
Exhibit 39: C-0112 -Shield Building Details © 2012. Performanc e Improvem e nt International-Appendix A B c o .'>>D' Exhibit 39 M;AIJlIIiDNe '\.;::;;t L: J y = ---, L S4"'LAWT(I>YM: IlIGtESl*(WI'!. SECTION ELEVAl"IOl!I .....-=.....j(f'talllCf'/59 DETAIL DETAIL SCA .. -("-J -,uq I SECTION @ $CALf: #&' ",t, .. ...,...=-== ..".M .... ...-..(11..."... ." Page 1 of 1 _ secn'l:N $c.<<.e!:?'w
to" W&I& t8(Il't$ "'t.t II!GLU --OEtfOTU \lWiI$YOP
+OlM016 1$"8I.DI:KW1 JoR 8.1Cf1l\CAl POIttunoll ...DtNOTES;ste1..OOO)U1' fOR 8.ICJRKAl PbIlRATKlI
DQIOfES..-8lt)Q(()Ul$
NOTES I _-..a_am...tl, t .....rn.._at.r:1'Itlw. ...nl1.Ift .....r-4tt _1-_ t: ....UIIIf.4lD..-.w......'IASl..._. c*.. r-.c--m* A B o E Exhibit 40: C-Oll1 -Shield Building Wall Development © 2012. Performance Improvement International- _ Appendix 0' J.". Exhibit 40 I ..,....*.. _1-I ------It r EL.!!I11 1</<>1.,70' .'./, @.'..._curu,>u'..""""'"-r* ".-' Lc Ai" .41t"VND _ , !flU". 46 IJNONN .D:ETAI.I.. @ $CA4..f ; .. PENETRATION
29. ijf--,,:.
LW.._= A<<J'f /XIi.:r:s 5'b <;" 5' i . .. fb"M,"' ___ 90" ! r. DETAlL@/"'*#0" I
\ ,,11 ..., lff' ,,,,. ** Pocxif'T + DENOTES 1Iif'ELECTRtCAl.
PENe'TRATION
..,.. DENOTES 32"t:LECTR<<:A\.
PEt£:TRATION. ":I-. __'JI'!Inru.n .. IIIIJI&_tl..
..
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..
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J;:vj jr -"",,,-,,, . FOR._FCR EiO!O"'4 CLASS I STRUCTURE
" '" -.} .....
REFERENCe: DRAWlt@S FW.lI't::RF.M:£ DAAWttf.l$ sea DRA'MIoIG C.tlO C'1I2 SHIEll) au.JLOfMG ClC:V\U.S SH.-", 1 A B Exhibit 41: C-0110 -Roof Plan Wall Section Details © 2012. Performance Improvement International- _ Appendix VIII*42 'It./. ,ey @ -" COHYIt..,fC' ",,'. -"& 1't:M: $,c?FJff OF r.e1f4T./a1'ff INA /JIItrtJI, C-N# Pt.A/I Pc*u..&*v"*.?d ,FC';ltilq Jt,£t1UAONfMl.. WllNa ()M'" PJ..AIi fX'JlU: ,,"./1'0' TYPICAL '*pINFO:/tC/Nfii SPl.lcES -/f " H ?1 ...... ... " '" '" u-CLASS I 5r,el/cr!J£F C.1lI (.'QMWL, C"tl'IW'.oeACr 77".,.8 WAlt. ,IN.- fDl>o.' Q(;J!IIII,I Ctt4'C, NIl. -(uN!!) UMYlcmo", Ual'llflJ,l AU RliljEI nTEllSTQPStllALlBESItlUrTn ' NO RlGKflll SIIlll i£ fIt.AUfI WillIs;) tll£ STt:UC1'UK I¥rtl. COIK'IRt'lt. IllS OIlAIIO SOfFIelOO 'TltIllllrli ,.. MElII!RANE ua'COICl.'II'VCTlt11 ootlilm If. ,II C e, ACI 1II1'U "&UNIMIi toOl UIIu'lf>>:m fOt Ulllf..m£8Mtllrt£i' .. ACI tJJt. ",I!£.C1F\CA'rIQM F1IR STf!l,K:1UMlt.llllCKf( 1I'000,UU.llUIIl$". ' 4. AtIMlll\llolGFGCIatl!m'PIbICHCf, 1t8t', RUllI, t, Alii B ACt or et:I_n lentflOk fOft POIIfUlll .. 110;. nu.c*:a II D Exhibit 42: Entire Structure, 11*23 © 2012. Performance Improvement International-Appendix Exh i bil42 Figure 1: Impulse Response Average Mobility Values Through 22 November 2011 Shield Building Exterior Elevation Flute Number 8 7 6 5 4 3 2 Sl'Iouldcr Shoulder Shoulder Sl'Iouider Sl'Iouldcr 800 800 780 ---fIIIf"' I I (III 780 760 -+-1 I I I I I I I II " " " I 760 740-1 I I I I I I I I II _ II II II 1 740 g 720 ] I I I I I c o II II II I 720 700 -H I I -I I I I I I I I I I I I I 700 >,S! W 680-1 I I L I I I I I " " " I 680 _i.. ..... 660 I I I---M II II 660 **n,. I I au 640 -t-l I 640 62011:== =11 II I I I I I I I I I 620 600 I i I I j I I i I I I I I i I Ii! I i I Ii! 600 22.5 o 337.5 315 Legend Average Mobility Color Scale I 0.3 0.4 0.45 0.5 Exh i bil42 292.5 270 247.5 225 ¢ Impulse Response Test Location
Untested Area 202.5 180 Azimuth 157.5 135 112.5 90 67.5 45 CTi}CiRouP CONSTRUCTION TECHNOLOGY LAB-QRATORKS EHmi"tc.UI:5 IJ,. CONSTJIIUC"UQN TE(:HMOLOGY CONSULTANTS 5400 OLD ORCI-IARD ROAD SKOKIE, ILLINOIS 60077-1030 PHONE: 847-965-7500 FAX:
www.CTLGroup.com Davis-Besse Nuclear Power Station Oak Harbor, OH ISSUE No. Descriplion Dale CTLGroup No.: 262600 Drawn: AMS/SEH Checked: CAO/ECD Date: 22NOV11 Scale: NTS Revised Test Area 28 123NOV11 Impulse Response Mobility Plot Figure No.: 1 Exhibit 43: Calc. C-(55-099.20-054 Rl (FENOC Document -Not Included as an Attachment to this Report) © 2012. Performance Improv e ment International -Appendix VIII-44 Exhibit 44: Drawing (FENDe Document -Not Included an Attachment to this © 2012. Performance Improvement International -Appendix VIll-4S Exhibit 45: C-0100 Shield Building (FENOC Document -Not Included an Attachment to this © 2012. Performance Improvement International-Appendix VIII-46 Exhibit 46: Shield Building Inspection Overview Appendix VIII-47© 2012. Performance Improvement N0 ..... Q) 0> ro (/) : ,. .a.. Q) c I-..... C'O t:: 0 N o N <1> 0) ro a.. Exhibit 47: E-0401lighting & lightning (FENOC Document -Not Included as an Attachment to this Report) © 2012. Performance Improvement International Appendix VIll-48 Exhibit 48: 1995 -0395 Lightning (FENDe Document -Not Included as an Attachment to this Report) © 2012. Performance Improvement International-Appendix VIII-49 Exhibit 49: Corrosion Related Photos (FENDC Document -Not Included as an Attachment to this Report) © 2012. Performance Improvement International-Appendix VIII-50 Exhibit 50: Calc. C55 090.022-056 Rev (FENOC Document -Not Included an Attachment to this © 2012. Performance Improvement International Appendix VIII-51 Exhibit 51: Freezing and Rebar Spacing Study © 2012. Performance Improvement International -_ Appendix Exhibit 51 -Appendix Freezing Failure Mode Rebar Density Modeling Results Performance I nternationa I Feb 13, PII Page 1 142 _2012 2/23/2012 CL ""C c: Q) << I.{) :.0.s:::. x, W N <:I' rl 0 ("'") (J) 01 C1l C4 u.. '-D'* > 0 N I ..-; N o c.... N ..-; N ff"l N N 0 N "0 r-I c:: Q) 0.. \lEt 0.. 0<< (])l() 01 III:00..:E ><W LL. > \D*0 a:.... << 0... ea w V') a:........ ::J W V') Q) 0::::: V) b.O Z c: N Q) W N Q) C M 0!..... N U. m N Exhibit 51 -Appendix Dense Rebar, 0.6%
This section of results are from a model with the following parameters:

0.6% VF i.e. 0.6% of the elements in the first 0.1" under the horizontal rebars (bottom 180°) are given a 7% expansion to simulate ice freezing. Dense rebar -Assumes some sub-6" spacing (2" to 6" centers) -Based on the photo earlier in these slides PI! P a ge 5 0:15 l 4 2 2/23/2012
_ 2012 Exhibit 51 -Appendix Mesh: Dense z z Standar y 1.. 2/23/2012 PI I Page 6 0:11; 1 4 2 _ 2012 Exhibit 51 -Appendix Outer 2" Frozen (7% Dense Rebar, 0.6% Ptt 2/23/2012 Page 7 of.! _ Exhibit 51 -Appendix Outer 4/1 Frozen Dense Rebar, 0.6% VF da PII 2/23/2012 Page 8 0& _ Exhib i l51 -Appendix Outer 6" Dense Rebar, 0.6% z Incre Primary Var: DAMAGET P I I 2/23/2012 Page 9 019 1 4_ Exhibit 51 -Appendix Outer 8" Dense Rebar, 0.6% z .....-....-..-_. ---------..-..--------.....-.. -.---.-.-------------......-.-----_ .._. -.--------da Primary Var: 2/23/20.12 . PII Page 10 q1{) 14;2 _ 2012 Exh i bit 51 -Appendix Outer 10" Dense Rebar, 0.6% z y xStep : Increm Primar y Var: DAMAGET Debonding (failure between concrete and steel) PII 2/23/2012 Page 11 <:111 _ Exhibit 51 -Appendix Inner 6/1 @ 1% Dense Rebar, 0.6% z Increment Primary Var: DAMAGET PII 2/23/2012 Page 12 q i2 _ Exhibit 51 -Appendix Inner 6" @ 2% Dense Rebar, 0.6% z Inc r ement P r imary Var: DAMAGET PI!2/23/2012 Page 13 <1 13 _ Exhibit 51 -Appendix Inner 6/1 @ 3% Dense Rebar, 0.6% z Increment Pri mary Var: DAMAGET forming between bars PII 2/23/ Page 14 . q.1l\. _ Exhibit 51 -Appendix Inner 6" @ 4% Dense Rebar, 0.6% z Increm Primary VClr: DAMAGET PII 2/23/2012 Page 1 5 _ Exhibit 51 -Appendix Inner 6" @ 5% Dense Rebar, 0.6% z y xStep: Increme Primary Var: DAMAGET PI 2/23/2012 Page 1 6 q:fi; _ Exhibit 51 -Appendix Inner 6" @ 6% Dense Rebar, 0.6% z y Increment Primary Var: DAMAGET PI!2/23/2012 Page 17 qr:; 142 _ 2012 Exhibit 51 -Appendix All Frozen (7% Dense Rebar, 0.6% z y Increm Primary Var: DAMAGET PII 2/23/2012 Page 18 C!18 1 4 2 _ 2012
Exhibit 51 -Appendix Freezing Results NOMINAL 6" REBAR, 0.6% VF PII Page 19 142 2/23/2012
_2012 Exhibit 51 -Appendix Nominal 6" Rebar, 0.6%
This section of results are from a model with the following parameters:

0.6% VF i.e. 0.6% of the elements in the first 0.1" under the horizontal rebars (bottom 180°) are given a 7% expansion to simulate ice freezing. Nominal 6 11 spaced rebar -Assumes 6" spacing and includes lap regions PII Page 20 <00:],.42 2/23/2012
_2012 Exhibit 51 -Appendix Mesh: Nominal 6" Standi: y PI Page 2 1 qm 1 /23/201 2 _ 2012. Exhibit 51 -Appendix Outer 2" Frozen (7% Nominal 6" Rebar, 0.6% fic Standc PII Page 22 _ 2/23/2012 Exhibit 51 -Appendix Outer 4" Frozen Nominal 6" Rebar, 0.6% VF Standc PII 2/23/2012 Page 23 _ Exhibit 51 -Appendix Outer 6" Nominal 6" Rebar, 0.6% fic Standc PII Page 24 14 2 2/23/2012 _ 2012 Exhibit 51 -Appendix Outer 8" Nominal 6" Rebar, 0.6% Standc PII Page 25 c:lfS 2/23/20.12 _ Exhibit 51 -Appendix Outer lO" Frozen Nominal 6" Rebar, 0.6% VF cific Stand" 2/23/2012 PII Page 2 6 C$ _
Exhibit 51 -Appendix Inner 6" @ 1%
Nominal 6" Rebar, 0.6% fic Stand;: PII Page 27 Ci!l142 2/23/2012 _ 2012 Exhibit 51 -Appe n dix Inner 6" @ 2% Nominal 6" Rebar, 0.6% Standc PII Page 28 c£18 142 2/23/2012 _ 2012 Exhibit 51 -Appendix Inner 6" @ 3% Nominal 6" Rebar, 0.6% flc Standi: P I I Pa ge 29 _ 2/23/2012 Exhibit 51 -Appendix Inner 6" @ 4% Nominal 6" Rebar, 0.6% Stand.: PII Page 30 qp() 142 2/23/2012 _ 2012 Exhibit 51 -Appendix Inner 6" @ 5% Expansion Nominal 6" Rebar, 0.6% VF c Standc PII 2/23/2012 Page 31 c;Bfl142 _ 2012 Exhibit 51 -App e ndix Inner 6" @ 6% Expansion Nominal 6" Rebar, 0.6% VF Stand;: 2/23/2012 PII P a ge 32 <Bf2 14 _ Ex h ib i t 51 -Appendix All Frozen (7% Nominal 6" Rebar, 0.6% Standc PI! Page 3 3 1 42 2/23/2012 _ 2012 Exhibit 51 -Appendix Freezing Results 12" VERTICALS ONLY, 0.6% VF 2/23/2012 PI! Page 34 <8f4 _2012* Exhibit 51 -Appendix 12" Verticals Only, 0.6%
This section of results are from a model with the following parameters:

0.6% VF i.e. 0.6% of the elements in the first 0.1 under the horizontal rebars (bottom 180°) are given a 7% expansion to simulate

Nominal 12" spacing of verticals only -Assumes 12" spacing and includes lap regions -Horizontal bars stay at 6" nominal spacing PI! Page 35 Qlf5 142 2/23/2012
_2012 Exh i bit 51 -Append ix Mesh: 12" Verticals z Standa y PII 2/23/2012 Page 36 c;Bfb142 Exhibit 51 -Appendix Outer 2/1 Frozen (7% 12" Verticals Only, 0.6% c Standa PI! Page 37 CftfI142 2/23/2012 _ 2012 Exhibit 51 -Appendix Outer 4" 12" Verticals Only, 0.6% Standa PI! Page 38 c:m3 142 2/23/2012 _ 2012 Exh i bit 51 -Appendix Outer 6" 12" Verticals Only, 0.6% Standa PII Page 39 <3f9 142 2/23/2012 _ 2012 Exhibit 51 -Appendix Outer 8" Frozen 12" Verticals Only, 0.6% VF Standa 2/23/2012 PII Page 40 QlIb 1 _ Exhibit 51 -Appendix Outer 10" 12" Verticals Only, 0.6% ific Standa P li Page 41 atfl 142 2/23/2012 _ 2012 Exhibit 51 -Appendix Inner 6" @ 1% Expansion 12" Verticals Only, 0.6% VF ific Standa /23/201 2 P I I Page 4 2 QjQ 1 _ Exhibit 51 -_ Appendix Inner 6" @ 2% 12" Verticals Only, 0.6% Standa Pl Page 43 aJf6 2/23/2012 _ Exhib i t 51 -Appendix Inner 6/1 @ 3% 12" Verticals Only, 0.6% Standa PII Page 44 QIlil142 2/23/20.12 _ 2012 Exhibit 51 -Appendix Inner 6/1 @ 4% 12" Verticals Only, 0.6% fic Standa PII Page 45 Gl'/l5 _ 2/23/2012 Exhibit 51 -Appendix Inner 6" @ 5% 12" Verticals Only, 0.6% fie Standa PII Page 46 016 142 2/23/2012 _ 2012
Exhibit 51 -Appendix Inner 6" @ 6%
12" Verticals Only, 0.6% Standa PII 2/23/2012 Page 47 ctfl 1 _ Exhibit 51 -Appendix All Frozen (7% 12" Verticals Only, 0.6% 5tanda PII Pag e 48 QJ!8 1 42 2/23/2012 _ 2012}}

ML12138A067

Contents

Text

1.4.2 Compatibility

1.4.5 Water

2.2.2 Monitoring

2.1 provides

2.2.5 Blasting

2.2.5 Blasting

2.2.6 Cullmg

2.2.8 Milling

2.1 Properties

2.2 Material

2.2.3 Material

2.3 Process

2.4 Concrete

2.4.3 Aggregate

2.4.7 Steel

SUMMARY

3.0.3 Unusual

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ML12138A067

Text

1.4.2 Compatibility

1.4.5 Water

2.2.2 Monitoring

2.1 provides

2.2.5 Blasting

2.2.5 Blasting

2.2.6 Cullmg

2.2.8 Milling

2.1 Properties

2.2 Material

2.2.3 Material

2.3 Process

2.4 Concrete

2.4.3 Aggregate

2.4.7 Steel

SUMMARY

3.0.3 Unusual

Navigation menu

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