ML19221A925

Reg Guide 1.107,Revision 1, Qualifications for Cement Grouting for Prestressing Tendons in Containment Structures

ML19221A925
Person / Time
Issue date:	02/28/1977
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
References
REGGD-01.107, REGGD-1.107, NUDOCS 7907100394
Download: ML19221A925 (7)

Text

Revision 1

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U.S. NUCLEAR REGULATORY COMMISSION Fet'ruary 1977

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OFFICE OF STANDARDS DEVELOPMENT REGULATORY GUIDE 1.107 QUALIFICATIONS FOR CEMENT GROUTING FOR PRESTRESSING TENDONS' IN CONTAINMENT STRUCTURES A. INTRODUCTION B. DISCUSSION General Design Criterion 1. "Quaht) Standards The recommendations of this guide are appheable and Records.' of Appendn A. " General Design when portland cement grout is used as the corrosion Cnteria for Nudear Power PlantC to 10 Cl R Part mhibitor for the highly stressed tendons of prestres-50 "I.icensmg of Production and Utilization sed concrete containment structures. The recommen-I acihties.' requires that structures, sy stem s, and dations of the guide are not intended for use in rela-components important to sa fe t y be designed, tion to the grout for foundation anchors.

fabricated, and erected to quality standards commen-surate with the importance of the safety functions to To date. the staff has esaluated appheations be performed.

proposing grout as the corrosion protection system for both bar tendons and strand tendons. The recom-The prestessing tendon sistem of a prestressed con-mendations of this regulatory guide therefore apply a grouted tendon system when the tendon is crete containment structure is a prir.cipal strength to element of the structure. Since the abiht) of the con-fabricated from c;ther bars or strands. For grouting tainment structure to withstand the esents postulated of wire tendons a program based on simdar quality to occur during the hfe of the structure depends on standards may be des eloped and submitted to the the functional rehability of the 3tructure's principal staf f f or es aluation.

strength elements, any ugmfican'. deterioration of the prestressed elements due to corrosion may present Unlike greased tendons. grouted tendons are not potential risk to the public safety llence it is imror-asailable for direct inspection after they are grouted.

tant that any system for inhibiting corrosion of the it is therefore essential that the proposed grout and prestressing elements po sess a high degree of grouting procedure be thoroughty es aluated before it rehabihty in performing its intended function.

is used in the construction of the containment strue-ture. An adsantage of grouting, in addition to This guide describes quahty standard, acceptable prosidmg corrosion protection, is that a w ell-to the NRC staff for the use of portland cement grout designed and well-constructed grouted tendon system as the corrosion inhibitor for prestrewing tendons in prosides a degree of bond between the tendons and piestressed concrete containment structures. The Ad-the surrounding concrete. This bond in turn helps the sisory Committee on Reactor Safeguards has been anchorage system to resist the fluctuating strewes consulted concerning this guide and has concurred in that arise after construction of the structure.

the regulatory position.

Section 111. Disision 2. " Code for Conciete Reac-f or the ruiroses of the FxJe. a "te*n" de h ed,,

tensued steel elemert uns:sw of mres. s: r a c J s. or bar-tor Vewels and Containments," of the ASME iloiler ansbored at cah end ia an end anshorage anembb and Pressure Vessel Code (Ref.1) prosides some re-t ns mJs te #:anme sham from rrew nwe, quirements for grout constituents and for the USNHC REGULArORY GUIDES c.m ~,, ow, r.

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phs uc il anJ chemical properties of grout.

Ihe limits recommended for ehlorides, n it ra t es.

Reeulators Po ut io n C.1 of this guide brie fly sulfates, and sulfides in Regulatory Position C.I.e i

dewribes mmimum quahty standards for grout should not be exceeded m the oserall composition of noteriah. refer en cm e the ASME Code Articles the grout. T he quantities of these substances in the w here apph;able and acceptable to the NRC edf.

grout constituents should be determmed indnidually The regulatory poution also outhnes important con-for each of the constituents by the appheable AST M siderations allectme proper grouting. References 2. 3.

( American Society of Testmg and M aterials )'

and 4, as well as data furnished by applicants w ho methods and esprewed in parts per nullion parts of h.n e proposed grout as the corrosion inhibitor for water in the grout composition.

prestressmg steel. hase been used to arrise at thn poution.

In general, portland cement conforming to ASTM C150. Ty pe I or Type !!. n suitable for the grout.

\\ppenda A to this guide prosides a lht of relesant f low es er, eroutine under certam climatie or en-hterature that m.n be used by the apphcant to es-sironmental conditions mas dictate the use of other tabinh procedures and criteria for the specilie tsres of cements. Chloridek are normally present m grouted tendon progrant flowes er. the hsting of cement, but the amount h usually not reported. T he these references does not constitute a blanket en-deternunation of chlorides m cement should be a re-dorsement by the staf f of their content.

quirement w hen specify mg the cement for grout.

Specifie areas of concern that should be enen Admatures should be free of. arn substance likely proper attention during the deselopment of a grouted to damage the prestrewine stee!. be of aluminum tendon sutem are discussed m the folhiwing pa r a g r a p h's.

piwWu to produce npans on has been siewed by I many engmeers as hasing posuble deleterious ef fects.

T he eff ectn eness of grout in performing its m-Under an alkaline ensironment (pli 9). the tended f unction of inhibning corrouon depends alununum pow der eenerates minute bubbles of mamly on tw o characterntics-hydrogen g n (ll.) that would not endryer the ten-stoned steel at the presailm range of prewures and i

I. I,ne grout t whether freshly mned or hardened) tem perat u res. Ilow es er, the potential danger o f- {

d ould not cause chemical attack on the prestressme hydrogen attack on steel does esist if the tenuoned l i

elements through its mteraction with tne material of steel elements or stressed anchorage compone its con-the tendon steel, the material of the anchor hardw are, t.un surf ace flaw s. The ;uramet.rs af fectmg the use of

or the material of the duct.-

alummum powder are described in Reference 9.

2. I he groot should completely fill the tendon duct on hardemng.

T he proteetne mechanism of grout is primarily dependent on its abihty to proside e continuous Vanous deletenous substances hase been reported aRahne ensironment around the tensioned steel ele-l as potentui sources of corrosion of prestressmg steel ents Ihe natural alkahnity of the primary product J Most of the reported f ailures of prestrewmg elements of cement hs dration (i.e., calcium hy droxide) tends to !

h.ne been attributed (a) to the presence of chlorides he at a pli salue of 12.5. The effectisenew of the {

in the atmosphere or m the constituents of erout or ahahne ensironment nu) be reduced by the leaching j th) to the presence of hydrogen sulfide in' the at_

of alahne ubstances with water, by reaction in an l mosphere ( Refs. i 6. and 7). Nitrates and sultates aadie or sullide-containing en.ironment, or by the eenera!h !ound m mnine water h.ne been theorized prgence of ou een and chloride ions. It is reported in Rdnence 10 that the ability of chloride ions to to be potential sources of strew corrosion of prestrewmp steel llow es er, it has been reported des elop conouon in a m es with deercasing (Ret M that. m a wnerete ensironment, ou eenated ahahnny of the calaum hydroude solutiont 'Ihus it anions such as sultates and nitrates do not edihit in.

n adusable to monitor the pil s alue of the in-place,

tense corrouon properties. it has aho been reported grout under actual ticld conditions and ensure that it !

(Ref. H that most of the chlorides are neutrah/ed TC"'""' dh"C d "I"C " here the pawn ating effect of, l durmg the hydration of portland cement. The the grout is not reduced by the as atlable chloride ions threshold s alues below which these substances will m the composition of the grout.

not participate m mitiating corrosion base not been Section CC-22412 of the ASMI. Code (Ref.1) re-established Ilence a safe and prudent approach quires the use of tion cones with the hmits on ett,.us would be to make sure that these substances are I

times at the spec:.h.e quiescent times to ensure ade-knu.ed to the lowest practical lesels in grout con-quate lluidity of the grout. Ilow es er, f.or certam ty pes stituents. Ihe use o f. w ater contammated w it h hydrogen sulfide should be prohibited of grouts un particular one with a thnotropic ad-ditne), these requirements may not be appropriate to I or the purpmes of thn gmde a "d at" aa ho'e er s oid defme their pumpabihty. Applicants in such cases prm &d d the cor'erete for the past. tens:on mg tendien A d a..t nm be prouded bs emNddmg metal deathmg m tauon. plate

' \\ hst of retemt MTN1 undards a prmiJed m Apperda B of m ace tha emde 126 163 1.107-2

should propose alternatise means of quahty control

1. \\lateriah to accomp!nh the same objectise. Also, a ceneral practice is to limit the pumping pressure durmg

a. Portlaml Cement. Cement should conform to grouting to Ju) psi (see Res 2 and 3). Ilow eser, the requirements of ASTN1 C150. The type to be grout with a thnotropie additise may need higher selected should be suitable for the intended use.

pumping pressures for long sertical tendons. In such cases, it should he demonstrated through tests that

b. /ir:c lecrceate 1 na aggregate-fdler may be high pressures will not deteriorate the quality of.

used w hen permitted by the equirements of Article grout; damage the duct. duct sphces, or surroundinF CC-2243.1 of the AS\\1E Boder and Pressure Vewel concrete; or deform the containment liner-Code. Section 111. Ibision 2 (Ref 1).

In addihon to the control on grout materiah and on mismg and injectme the grout to ensure the in_

c. W ater. The w ater should not contam m.

tended protection of the'prestrenmg steel,it is impor-Fredients harmf ul ta the prestressing steel or the tant to take other precautions directh related to the grout. Water contaminated (I ppm) with hydragen I corrosion protection of the prestrewine steel sulhde (sultide ion) should be prohibited. The water to be used for grouting should be qualified for use by I. It is necewary that the tendon remain clean, dr).

making comparatise tests in accordance with the test tr~ from Ale'erm e<strmi 'n and undamaged up methods and tolerance lesels described m Article CC-to the time it is grouted. Specifie protection raeasures 2223.2 of the ASNIE Code.

should be prosided at coastal sites, at sites hasing a high moisture les el, and at sites near industriai arcat

d.. htmn tJrct Acceptable admixtures may be used if tests base demonstrated that their use

.. % hen a preassembled tendon 4 heath.mg as-

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sembly is to be placed before concreting, the tendon uorkabihty, reduces bleedmg, presents w ater separa-should be proteted q.tinst corrosite ensironment nu n pum at @ pwure, ennns & &

durmg as sem h-handline, stormg. transportine, placing, and ten ionmg.

panes the grout, or reduces shrmkage. The quantities of harmful substances in the admixture should be

3. Hefore placing the tendon in the duct. it is im-kept to a minimum. Use of calcium chloride should portant to ascertain hat the duct is free of obstrue_

be proNbited.

tions, moisture, and o;her dcleterious substances.

c. l.imits on Ihleter;ow Substances and,11.

7

4. I errous metal sheathing n gahanized to protect it against corrosion before grouting of the tendon (1) The quantity of the following substances lioweser, the contact surfaces of the tendons and the (added indnidually for each constituent and expres-sheathing are potential areas for the formation of sed as parts per million parts of water)in the oserall corrouon cells and hydrogen esolution. I rom the grout composition should not exceed the followmg tendon cerrouon point of siew, this is critical if the hmits:

time between the tensionmg and grouting is long and the duct contains moisture with or without Chloride 100 ppm deleterious substances.

(200 ppm if pil is maintained t abose 12)

I

5. In general, the period between tensioning and

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j grouting is critical from the standpoint of stress cor-Nitrates 100 ppm

! rosion or hydrogen strew cracking. Steps should be l

! taken to minimize this time period S ulfates' 250 ppm E ffectis e corrosion protection of prestrewing Sulfides 2 ppm (test method of Ref.15) {

tendons can be prosided by portland cement grout it appropriate precautions are taken to eliminate the potential sources of corrosion. To this end, close (2) The pil value of the grout at inlet and outlet of the duet shou!d be maintained abose 11h(12 if the quahts control :s neces<ars for each constituent of

",lowable chloride content is 200 ppm).

the gr'out, the tendon material, and the tendon duet

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material and for the method of mixine and pumpine the crout and ensurine that the tendoriis surrounded (3) Durmg the grouting period, the amount of froni end to end with quahfied erout.

deleterious s u bst a r.ces in the grout constituents should be checked weekly and w heneser the composi-C. REGULATORY POSITION tian of the constituents is changed or is suspected of hasing changed The followmg minimum quality standards should 9

be maintained when portland cement grout is to be

' Ufees in the form of su: fur trioude as a tement component used for the corrouon protection of prestressing steel.

neta r.ot ne wnuderca 1.107-3

2. Phpical Properties of the Grout should be protected f rom inclement weather and other adserse er,sironmental conditions durmg this The physical properties of the cement grout should period if an additional delay is espected, the tendons satisfy the reqmrements of Article CC-2243 2 of the should be p;otected by methods or products that ASN!F Code Ndequate tests should be carried out in uould nat jeopardve the effectiseness of the grout as nordanse with the test methods described in that a corrosion inhibitor. In any case. the tendon artale to demonstrate that the grout satisfies these re-anchorages should be sisually examined just prior to qmrements groutmg to detee any breakege or degradation of prestrewog elements as esideaced by the mosement 1 U"'I or dnlocation of anchorma h..rdw are.

T he duet sue should be adequate to allow the a

b. i 'u s..

a before grouting n not recommended.

msertion and tensioning of tendons without undue When nu, > ag has to free:de the grouting, ap-l ddliculty. The area of the grout that penetrates and surrounds the tendon at any section shoukt ne at least proprute measures should b: taken to ensure that: l equal to the cross-sectional area of the tendon. The duct sheathing and its sphees should be of ferrous (I) The lesel of harmful substances in the in-metal and should be protected to present corrome place grout does not increase abose that in the deterioration prior to the grouting of tendons The designed grout, and duet sheathing and its splices should be suf ficientis tight that a thin cement slurry cannot pass through (2) I he properties of the mjected grout sainfy

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whde the surroundmg concrete is bemg placed. The the recommendations in Regulatory Position C.1 duct sheathing and its sphees, w hen surrounded bs Tests should estabhsh the length of time that the

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hardened concrete. should be capable ot grout can be used afte mning. The tests should withstand ng the maximum groutmg pressure without leakage.

vily that:

b. Vents should be prouded at any maior changes t1) The miended reaction of such admistures as m ution of the duct. as well as at the high po.nts.

espanme agents contmues w hen such a grout n m-

- Drams should be prosided at the low pomts. Vents jected in the duct. and

! and dr.uns should be checked for powbie obstruc-l tions prior to groutmg.

t2) This time is less than that required for the in-itial set of the grout a determmed by the method of

4. Equipment for Grouting AS T N! C191.

a. The grouting equipment should melude a miser that n capable of continuous mechamcal mning and

d. The temperature along the entire length of the l that can produce a grout free of lumps and un-tendon duct durmg groutmg should be abose 35*l.

dnpersed cement. To this end. tests should be per-This temperature sh,uld be maintained until the formed to demonstrate the optimum range of mixing mimmum (2-inch cube) strength of the job sured time and the sequence of plaemg the constituent grout exceeds M0 psi. T he grout temperature should materials in the mner under estreme anticipated en-not exceed 904 during mning and pumpng unless it sironmental condmons.

can be established by test that a hieher temperature I will not adsersels affect the croutme operation.

b. T he pump should be of the positne displace-

~

ment type and should be capable of exertine the re-

e. T he deulopment of the grouting procedure quired m.nimum pressure. A saf ety desice should be should consider the estremes of anticipated en-prouded to guard against exerting a pressure that sironmental conditions. The r rocedure should ensure could Jamage the duet, duet sphces, or surrounding that the ducts will be filled and that the tendon steel concrete or deform the containment liner. The pumps will be completely surrounoec by grout.

should not suck air in with the grout.

f. All openings, air sents and drains should he

c. A screen hating clear openings not more than hermeticalls sealed after grout ng to present the in-I m meh (1/4 inch for grout with a thisotropie ad-

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gress or w ater and other corro-ise acents.

ditise) should be prouded between the mixed grout and the pump to ensure that the grout does not con-if an applicant chooses to proside permanent tain lumps if an excessn e amount of lumps remam protection of the anchor hardware by means of i on the screen, the batch should be rejected qualified grout or concrete. the protection should be

5. Grouting prosided on the following bases:

a. Grouting should be carried out immediately (1) All esposed anchor hardw are should be,

after tensioning. The period between tensiomng and thoroughly examined before being provided with the l l

grouting should be kept below 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The tendon permanent protection.

126 165 1.107-4

(2) Ihe permanent protection should be 1.scept in those cases in w hich the appheant designed.ind constructed in a manner that would proposes an acceptable astern. itis e method f or com-pres ent the mtrusion of water and deleterious sub-pising with specified portions of the Commission's stanses to the anchor. ige component.

regulations, the guide will be used by the N RC staff on the followine baset 6.

lendon The tendon should be clean. dry tree f rom celeterious corrosion. and undamaged up to the time

1. Submittals in connection with construction per-grooted. The preassembled tendon mit appheauons docketed after l'ebruary 14. 1977 !

when it is sheathing assembly should be protected against cor-will be es aluated on the basis of this guide.

rom e influences f rom the time of assembls to the time of grouting.

"""a s in connection with operating license D. IMPLEMENTATION apphcations f.or plants u hose constrtiction permit ar-I he purpose of this section is to proside mtorma-plications were docketed prior to I ebruary 14.1977, i tion to apphcants and licensees regarding the NRC will be es aluated in accordance with the conimitment stat t's plans f or using t his regulatory guide.

made by the applicant in the cons ruction pernut 9

126 166 9

1.107 5

APPENDIX A REFERENCES

1. " Code for C oncrete Reactor Vessels and Con.

Aug. 1965. Copies nu) be obtained from the tainments.' American Concrete Institute Committee American Water Works Association,2 Park Asenue, 359 and American Society of Niechanical Engineers New York. N.Y.10016.

Subcommittee on Nuclear Pow er.1975. Copies ina) be obtained from the American Societs of

9. " Admist ures fo r Co n c re t e, American Nicehanical 1.ngineers, 345 E. 47th St., New Iork.

Concrete Institute Committee 212. Copies may be N.Y.10017 or from the American Concrete institute.

obtained from the American Concrete institute. P.O.

P.O. Bos 19150, Redford Stat;on, Detroit. N1 ch.

Bos 19150, Redford Station. Detroit. N1lch. 48219 4S219

10. Il a u sm a n, D.

A.

" Steel Corrosion in l

2. " Recommended Practice for Grouting of Post.

Concretef Materiah Protection. Nos ember 1967 l Tensioned Concrete. Prestressed Concrete li.stitute Copies may be obtained from the National Associa-Committee on Post-Tensioning, pubhshed in PCI tion of Cerrosion Engineers. 2400 West I oop S..

l Journal, Nos./Dec.1972. Copies may he obtained l{ouston. Tesas 77027.

from the Prestrewed Concrete institute, 20 North Wacker Drise, Chicago, Ill. 60606.

11. liarstead. G.

A.,

et al. " Testing for I.arge Cursed Prestressing Tendons,' Proceedmgs of the

3. * 'eport on Grout and Grouting of Prestrewed American Society of CisilI ngineers. Power Dnisien.

Cont.ete. Proceedings of the Smenth Congrew of St arch 1971. Copies may be obtamed from the the i ederation Internationale de la Precontramte.

American Society of Ciul i ngineers. 345 I 47th 1974. Copies i.., be obtained from the Federation Street. New York. N.Y.10017.

Internationale de la Precontramte, Terminal flouse.

Grouenor Gardens. l.ondon SWIW OAU.

12 Iange, 11., "The Vacuum Procew, A N:w Niethod for injecting Prestressing Tendons.' paper

4. "Specificatians for Structural Concrete for submitted for the Sesenth Congress of the Federation Buildingsf American Concrete Institute Committee I n t er na tio n al,-

la Precontramte. New York N.Y.

301, 1972. Copies may be obtamed from the 1974. -

may be obtained from the i ederation American Corciete Institute. P O. Hos 19150. Red-Internationale de la Precontramte. Terminal flouse, ford Station. Detroit. \\lich. 48219 Gronenor Gardens. I ondon SWIW OAU i 1.conhardt. I. Prestrened Com rcre Deuen ar:d 1. Schupack, N!- " Des elopment of a W ater Comtruction. Wilhelm Ernst & Sohn, Berlin. Second Retentise Grouting Aid to Con rol the B!ced in Cc-I dition.19t4 ment Grout L sed for Poe-lensionmg." presented at the Sesenth Congress of the i ederation Inter-

6. S nationale de la P.econtrainte, New York. N.Y,1974 tion of(ilard. R..

"t,orrosion and C,orrosion Protec.

-'I#" "

Co nm be obtained from the address show n in i endons in Prestressed C oncrete Bridges.

s ACI Journal, Jan. 1969. Copies may be obtained from the American Concrete institute. P.O. Bos

14. Qfasi. S., et al, " Phenomena Associated with 19150, Redford Station. Detroit. N1ich. 4S219 Grouting of1.arge Tendon Ducts and N1orphology of DefectsJ technical contribution to the Sesenth 7 N1onfore, G. E and Verbeek. G. J., " Corrosion Concrew of the i ederation Internationale de la of Prestressed Wire in Concrete,' ACI Journd, July Precontrainte, New York. N.Y.1974. Copies may be 1960. Copies may be obtained from the address obtained from the address show n in Reference 12.

saow n in Reference 6.

15. " Standard Niethod for the Eumination of <

S. Scott, G N.. " Corrosion Protection Properties Water and Waste Water"-1971. Copies may be ob-of Portland Cement Con cret e.'

Journal of the tained from American Public ilealth Atsociation, imerican Water Works Association. Vol. 57. No. S.

10:5 ISth Street NW. Washington. D.C. 20036.

120

• \\ di i

1.107-6

APPENDIX B LIST OF RELEVANT ASTM STANDARDS C109 73. " Standard Method of Test for Compressise C494 71. " Standard Specification for Chemical Ad-Strength of ifydraulie Cement \\1ortars (Using mixtures for Concrete ~

2 in. C ube Specimens)"

D512-67, " Test for Chloride lon in industrial Water C4 50-74. " Standard Specification for Portland Cc-and industrial Waste Water" ment Concrete" D992 71. " Test for Nr. rate Ion in Water" C191-74," Standard Method of Test for Time of Set-D516-74, " fests for Sulfate ion in Water" ting flydraulic Cement by Vicat Needle

D596-74. "I,eporting Results of Analy sis of Wat :r"

) C260-74,

' Standard Specifications fo r Air-Dil29-74 " Terms Relating to Water" lintr.uning Admistures for Concrete '

D1293-65. "pil of Water and Waste Water" 126 168 1.10'-7

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O 126 169