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{{#Wiki_filter:s s Curin g Curin g Code s Code s g g g y and g y and h nolo g h nolo g te Tec h te Tec h C oncre t C oncre t C C Definition of Curing Curing-maintenance of a satisfactory moisture content andtemperatureinconcreteforaperiodoftime and temperature in concrete for a period of time immediately following placing and finishing so that desired properties may developImportant for all concrete, but particularly when:*Placing conditions result in rapid drying of fresh concrete*Concrete exhibits little bleedin g (e.g. silica fume concrete
{{#Wiki_filter:Concrette Tech C           hnolog gy and Codes s
)g(g)*Concrete develops properties slowly (e.g. fly ash concrete)
Curing g
Hydration Hydration of of c c e e ment ment Hydration Hydration of of c c e e ment ment P Portland ortland cement is a cement is a hydraulic cement: its hydraulic cement: its tilli tilli componen t s, ma i n l y ca l c i um componen t s, ma i n l y ca l c i um silicates, silicates, react with water


react with water to to formothercomponents formothercomponents form other components form other components called calcium silicate called calcium silicate h y drates h y drates--CSH (CSH (h y dration h y dration). ). y y (
Definition of Curing Curing - maintenance of a satisfactory moisture content and temperature in concrete for a period of time immediately following placing and finishing so that desired properties may develop Important for all concrete, but particularly when:
(y y)
* Placing conditions result in rapid drying of fresh concrete
)Hydration stops when
* Concrete exhibits little bleeding g (e.g.
( g silica fume concrete))
* Concrete develops properties slowly (e.g. fly ash concrete)


Hydration stops when internal humidity is lower internal humidity is lower than 80% or temp. falls  
Hydration of cement Portland cement is a hydraulic cement: its components, t mainly i l calcium l i silicates, react with water to form other components called calcium silicate y
hydrates hydrates- -CSH ((hydration y      )).
hydration).
Hydration stops when internal humidity is lower than 80% or temp. falls below 1414ºF
                  ºF


than 80% or temp. falls below 14 below 14ºF
Abrams 1919
ºF
: Abrams, Still holds in 2009?


Abrams1919 Abrams , 1919Still holds in 2009?
Why cure concrete?
Why cure concrete?Why cure concrete?
* To allow cement hydration progress and the concrete to develop its desired properties
*Toallowcementhydrationprogressandthe
* To prevent moisture loss from the plastic concrete (protect against plastic shrinkage cracking)
*To allow cement hydration progress and the concrete to develop its desired properties
* To o minimizee moisture o s u e loss oss from o thee concrete o eea  after e
*Topreventmoisturelossfromtheplasticconcrete To prevent moisture loss from the plastic concrete (protect against plastic shrinkage cracking)
setting (drying shrinkage)
*To minimiz e m o i s t u r e l oss fr o m th e c o ncr e t e a ft e r oeosueossoeoeeaesetting (drying shrinkage)  


Effect of the Duration of MoistEffect of the Duration of Moist--Curing on the Curing on theStrengthDevelopmentforConcrete StrengthDevelopmentforConcrete 40Strength Development for ConcreteStrength Development for ConcreteStrength gain of concretestored 30 M Pa)concrete stored in fog room (or immersed in lime t)20 Strength (M Continuous wa t er)-i.e.
Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete 40 Strength gain of concrete stored in fog room (or                     30 immersed in lime Strength (M S        MPa) water) t )
continuousl y 10 S Continuous curing ycured 0 Age (days)1371428 Effect of the Duration of MoistEffect of the Duration of Moist--Curing on the Curing on theStrengthDevelopmentforConcrete StrengthDevelopmentforConcrete 40Strength Development for ConcreteStrength Development for ConcreteIf concrete is not cured for a sufficient periodoftimeitwill 30 P a)period of time , it will not develop its full potential in terms of
20
- i.e.
continuouslyy                                                      Continuous cured                              10                           curing 0
1  3  7    14                      28 Age (days)


com pressive stren g th 20 r ength (M P pg (and other
Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete If concrete is not cured for a sufficient                      40 period of time, time it will not develop its full potential in terms of                      30 Strrength (MP Pa) p compressive  strength g
(and other properties).                                20 The pproperties p        of concrete close to the                                                      Continuous surface are                                10                            1 day particularly sensitive t curing to    i effects.
ff t Concrete at depth                            0 1  3  7    14                      28 will lose its moisture att a slower l      rate t                                            A (d Age (days))
when the surface is not protected.


properties).
Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete 40 As the duration of moist i t curing i isi extended -
T he p ro p erties of 10 St r Continuous 1 day ppconcrete close to the surface are particularly sensitive tifft 0A(d)1371428 t o cur i n g e ff ec t s.Concrete at depth will lose its moisture tlt Ag e (d a y s)a t a s lower ra t e when the surface is
30 concrete achieves Strrength (MP Pa) a greater proportion of its 20 maximum potential strength p              g Continuous 10                            7 days 3 days 1dday 0
1  3  7    14                      28 Age (days)


not protected.
Curing Requirements - ACI 308R- 308R-01 Basic Curingg Period 7 days above 50oF or Time to reach 100% of specified performance, including post post-curing curing gains Additi AdditionallCCuring i    R Requirements i       t Based B  d on Exposure
Effect of the Duration of MoistEffect of the Duration of Moist--Curing on the Curing on theStrengthDevelopmentforConcrete StrengthDevelopmentforConcrete 40Strength Development for ConcreteStrength Development for ConcreteAs the duration of itii 30 P a)mo i s t cur i ng i s extended -
concrete achieves agreater 20 rength (M P a greater proportion of its


maximum potential stren g th 10 St r Continuous 7 days 3 days 1d pg 0Age(days)1 d a y1371428Age (days)
Curing Requirements - ACI 308R-   308R-01 (Continued)
Curing Requirements Curing Requirements --ACI 308RACI 308R--01 01 Basic Curin g Period g7 days above 50 o F or orTime to reach 100% of specified performance, includingpost
St ct al Safety Structural    Safet Curing period extended until 70% of specified strength is reached Reinforced Mass Concrete 7 days or until 70% of specified strength is reached Unreinforced Mass Concrete 2 weeks without SCMs SCMs, 3 weeks with SCMs
-curinggains including post curing gainsAdditilCiRitBd Additi ona l C ur i ng R equ i remen t s B ase d on Exposure Curing Requirements Curing Requirements --ACI 308RACI 308R--01 01 (Continued)
(Continued)StctalSafet St ru ct ur al Safet yCuring period extended until 70% of specified strength is reachedReinforced Mass Concrete7 days or until 70% of specified strength is reachedUnreinforced Mass Concrete2weekswithoutSCMs3weekswithSCMs 2 weeks without SCMs , 3 weeks with SCMs Methods of Curing Methods of Curing1.Ponding or continuous sprinkling2.Absorptive mat or fabric continuously wet3.Wet sand or straw 4Spraycuringcompounds 4.Spray curing compounds5.Waterproof paper or plastic film 6.Vapor mist bath (precast)7.Forms in contact with concrete surface 8.Others,approvedbytheOwner 8.Others, approved by the Owner Methods of Curing Methods of Curing1.Ponding or continuous sprinkling 2.Absorptive mat or fabric continuously wet3.Wet sand or straw4.Spray curing compounds 5.Waterproof paper or plastic film film6.Vapor mist bath (precast) 7.Forms in contact with concrete f sur f ace8.Others, approved by the Owner Methods of Curing Methods of Curing1.Ponding or continuous sprinkling2.Absorptive mat or fabric continuously wet3.Wet sand or straw 4Spraycuringcompounds 4.Spray curing compounds5.Waterproof paper or plastic film 6.Vapor mist bath (precast)7.Forms in contact with concrete surface 8.Others,approvedbytheOwner 8.Others, approved by the Owner


Methods of Curing Methods of Curing1.Ponding or continuous sprinkling2.Absorptive mat or fabric continuously wet3.Wet sand or straw 4Spraycuringcompounds 4.Spray curing compounds5.Waterproof paper or plastic film 6.Vapor mist bath (precast)7.Forms in contact with concrete surface 8.Others,approvedbytheOwner 8.Others, approved by the Owner Methods of Curing Methods of Curing1.Ponding or continuous sprinkling 2.Absorptive mat or fabric continuously wet3.Wet sand or straw4.Spray curing compounds 5.Waterproof paper or plastic film film6.Vapor mist bath (precast) 7.Forms in contact with fconcrete sur f ace8.Others, approved by the Owner Methods of Curing Methods of Curing1.Ponding or continuous sprinkling 2.Absorptive mat or fabric continuously wet3.Wet sand or straw4.Spray curing compounds 5.Waterproof paper or plastic film film6.Vapor mist bath (precast) 7.Forms in contact with fconcrete sur f ace8.Others, approved by the Owner Methods of Curing Methods of Curing 1.
Methods of Curing
1.PondingPondingor continuous sprinkling 2.Absorptive mat or fabric continuously wet3.Wet sand or straw4.Spray curing compounds 5.Waterproof paper or plastic film C)film6.Vapor mist bath (precast) 7.Forms in contact with f m perature (o Cconcrete sur f ace8.Others, approved by the OwnerCuring Te m Methods of Curing1.Ponding or continuous sprinkling 2.Absorptive mat or fabric continuously wet3.Wet sand or straw4.Spray curing compounds 5.Waterproof paper or plasticfilm plastic film6.Vapor mist bath (precast) 7.Forms in contact with fconcrete sur f ace8.Others, approved by the Owner METHODS OF CURING METHODS OF CURING Membrane*SEAL IN MIXING WATERSpraycuringcompound Saturated Partially saturated Spray curing compound                Waterproof paper
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw 4
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface
: 8. Others, approved by the Owner


Polyethylene sheets Saturated*SUPPLY ADDITIONAL WATER PondingWater supplied from external source Ponding Soaker hoseWet sandWtbl source Sd W e t b ur l ap Immersion (precast)
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface f
: 8. Others, approved by the Owner


Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw 4
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface
: 8. Others, approved by the Owner
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw 4
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface
: 8. Others, approved by the Owner
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface f
: 8. Others, approved by the Owner
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface f
: 8. Others, approved by the Owner
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film mperature (oC Curing Tem          C)
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface f
: 8. Others, approved by the Owner
Methods of Curing
: 1. Ponding or continuous sprinkling
: 2. Absorptive mat or fabric continuously wet
: 3. Wet sand or straw
: 4. Spray curing compounds
: 5. Waterproof paper or plastic film
: 6. Vapor mist bath (precast)
: 7. Forms in contact with concrete surface f
: 8. Others, approved by the Owner
METHODS OF CURING                              Membrane Partially saturated
* SEAL IN MIXING WATER Spray curing compound            Saturated Waterproof paper Polyethylene sheets
* SUPPLY ADDITIONAL WATER Water supplied from external Ponding                      source Soaker hose Wet sand W t burlap Wet b l                            S Saturated  d Immersion (precast)
Steam curing (saturated air)
Steam curing (saturated air)
S aturate d


600 4Tensile Strength 500 3 Dr y in g StressCracking 400 3 yg n , p s i , M p a 200 300 2 T e n s i o n T e n s i o n ,8 in. (200 mm) wall73 °F (23 °C) temp.Fully Restrained Cement:517lb/ya 3 100 200 1Cement: 517 lb / ya(307 kg / m )W / C = 0.45 3 100 1 3 28 40 60Start of drying at 50% R.H.
600 4
7 1 28 40 60Age, days
Tensile Strength 500 Cracking Drying y g Stress          3 400 Tension n, psi                                                                            Tension,, Mpa 300                                     8 in. (200 mm) wall          2 73 °F (23 °C) temp.
Fully Restrained 200                                    Cement: 517 lb / ya 3 (307 kg / m 3 )
W / C = 0.45                 1 100 3   7      Start of drying at 50% R.H.
1                           28           40                   60 Age, days
 
Timing of Operations Heat Development Heat generated H            d Contact of cement and water setting 0                          2 to 3 Time (hours)
 
Evaporation of Surface Moisture from Concrete
 
Precautions to Minimize Plastic Shrinkage Cracking
* Moisten aggregates
* Cool aggregates and mixing water
* Dampen subgrade
* Erect temporary windbreaks and sunshades
* Cover concrete
* Fogg slab immediately y after placing
* Add plastic fibers
 
Fogging Good Fogging Bad Fogging Evaporation Retarders Curing Compound Applied to Fresh Concrete Moist Curing After the C
Concrete t HHardens d
 
Ad Adequate t curing i isi essential ti l
 
Wet burlap & plastic X


Timing ofTiming ofOperations Operations HeatDevelopmentHeatDevelopment Heat Development Heat Development d  setting Contact of cement and water nerate d setting H eat ge 0 2 to 3 HTime (hours)
Curing Membrane
Evaporation of Surface Evaporation of Surface MoisturefromConcrete MoisturefromConcrete Moisture from Concrete Moisture from Concrete Precautions to Minimize Plastic Precautions to Minimize Plastic ShrinkageCracking ShrinkageCracking Shrinkage Cracking Shrinkage Cracking*Moistenaggregates
*Moisten aggregates*Cool aggregates and mixing water*Dampen subgrade*Erect temporary windbreaks andsunshades and sunshades*Cover concrete
*Fo g slab immediatel y after gy placing*Add plastic fibers Fogging Fogging Good Fogging Good Fogging Bad Fogging Bad Fogging EvaporationEvaporationRetarders Retarders Curing Compound Applied to Fresh Concrete Curing Compound Applied to Fresh Concrete Moist Curing After the Moist Curing After the CtHd CtHd C oncre t e H ar d ens C oncre t e H ar d ens


AdtiitilAdtiitil Ad equa t e cur i n g i s essen ti a l Ad equa t e cur i n g i s essen ti a l W Wet burlap & plastic et burlap & plastic X Curing Membrane Curing Membrane X X Ensuring Adequate CuringEnsuring Adequate Curing*Curing should be a separate pay item in the contract*Contractor should submit a curing plan*The various tasks -initial, intermediate &
X
final curing
-have to made someone's specific responsibility*Adequate inspection required*Problems with curing-membrane systems?*Proper coverage/application


*Nothermalbenefit(+/-)No thermal benefit (/)*Bonding of subsequent overlay materials Field example, Field example,fll fll I f time a ll ows-I f time a ll ows-lhlh Examp l e w here curing was critica l on t h in low permeability shotcrete overlay: Specification Specification1/2 -in. thick6000 psi at 28 daysLess then 1500 coulombs rating (low permeability)Bondstrengthof200psiBond strength of 200 psiProject Climate: frequently hot and windy
Ensuring Adequate Curing
* Curing should be a separate pay item in the contract
* Contractor should submit a curing plan
* The various tasks - initial, intermediate &
final curing - have to made someones specific responsibility
* Adequate inspection required
* Problems with curing-membrane systems?
* Proper coverage/application
* No thermal benefit (+/-)
( /)
* Bonding of subsequent overlay materials


conditions  
Field example, Iff time allowsll Examplel where h  curing was criticall on thin h
low permeability shotcrete overlay:
Specification 1/2 - in. thick 6000 psi at 28 days Less then 1500 coulombs rating (low permeability)
Bond strength of 200 psi Project Climate: frequently hot and windy conditions


Questions-.
Questions.}}
Questions-.
Questions-.
Questions-.}}

Latest revision as of 16:01, 6 February 2020

1500 - E117 - Concrete Technology and Codes - 13 - Curing
ML12153A355
Person / Time
Issue date: 06/01/2012
From:
Office of the Chief Human Capital Officer
To:
References
Download: ML12153A355 (68)
v • d • e


Text

Concrette Tech C hnolog gy and Codes s

Curing g

Definition of Curing Curing - maintenance of a satisfactory moisture content and temperature in concrete for a period of time immediately following placing and finishing so that desired properties may develop Important for all concrete, but particularly when:

  • Placing conditions result in rapid drying of fresh concrete
  • Concrete exhibits little bleeding g (e.g.

( g silica fume concrete))

  • Concrete develops properties slowly (e.g. fly ash concrete)

Hydration of cement Portland cement is a hydraulic cement: its components, t mainly i l calcium l i silicates, react with water to form other components called calcium silicate y

hydrates hydrates- -CSH ((hydration y )).

hydration).

Hydration stops when internal humidity is lower than 80% or temp. falls below 1414ºF

ºF

Abrams 1919

Abrams, Still holds in 2009?

Why cure concrete?

  • To allow cement hydration progress and the concrete to develop its desired properties
  • To prevent moisture loss from the plastic concrete (protect against plastic shrinkage cracking)
  • To o minimizee moisture o s u e loss oss from o thee concrete o eea after e

setting (drying shrinkage)

Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete 40 Strength gain of concrete stored in fog room (or 30 immersed in lime Strength (M S MPa) water) t )

20

- i.e.

continuouslyy Continuous cured 10 curing 0

1 3 7 14 28 Age (days)

Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete If concrete is not cured for a sufficient 40 period of time, time it will not develop its full potential in terms of 30 Strrength (MP Pa) p compressive strength g

(and other properties). 20 The pproperties p of concrete close to the Continuous surface are 10 1 day particularly sensitive t curing to i effects.

ff t Concrete at depth 0 1 3 7 14 28 will lose its moisture att a slower l rate t A (d Age (days))

when the surface is not protected.

Effect of the Duration of Moist-Moist-Curing on the Strength Development for Concrete 40 As the duration of moist i t curing i isi extended -

30 concrete achieves Strrength (MP Pa) a greater proportion of its 20 maximum potential strength p g Continuous 10 7 days 3 days 1dday 0

1 3 7 14 28 Age (days)

Curing Requirements - ACI 308R- 308R-01 Basic Curingg Period 7 days above 50oF or Time to reach 100% of specified performance, including post post-curing curing gains Additi AdditionallCCuring i R Requirements i t Based B d on Exposure

Curing Requirements - ACI 308R- 308R-01 (Continued)

St ct al Safety Structural Safet Curing period extended until 70% of specified strength is reached Reinforced Mass Concrete 7 days or until 70% of specified strength is reached Unreinforced Mass Concrete 2 weeks without SCMs SCMs, 3 weeks with SCMs

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw 4
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface f
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw 4
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw 4
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface f
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface f
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw
4. Spray curing compounds
5. Waterproof paper or plastic film mperature (oC Curing Tem C)
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface f
8. Others, approved by the Owner

Methods of Curing

1. Ponding or continuous sprinkling
2. Absorptive mat or fabric continuously wet
3. Wet sand or straw
4. Spray curing compounds
5. Waterproof paper or plastic film
6. Vapor mist bath (precast)
7. Forms in contact with concrete surface f
8. Others, approved by the Owner

METHODS OF CURING Membrane Partially saturated

  • SEAL IN MIXING WATER Spray curing compound Saturated Waterproof paper Polyethylene sheets
  • SUPPLY ADDITIONAL WATER Water supplied from external Ponding source Soaker hose Wet sand W t burlap Wet b l S Saturated d Immersion (precast)

Steam curing (saturated air)

600 4

Tensile Strength 500 Cracking Drying y g Stress 3 400 Tension n, psi Tension,, Mpa 300 8 in. (200 mm) wall 2 73 °F (23 °C) temp.

Fully Restrained 200 Cement: 517 lb / ya 3 (307 kg / m 3 )

W / C = 0.45 1 100 3 7 Start of drying at 50% R.H.

1 28 40 60 Age, days

Timing of Operations Heat Development Heat generated H d Contact of cement and water setting 0 2 to 3 Time (hours)

Evaporation of Surface Moisture from Concrete

Precautions to Minimize Plastic Shrinkage Cracking

  • Moisten aggregates
  • Cool aggregates and mixing water
  • Dampen subgrade
  • Erect temporary windbreaks and sunshades
  • Cover concrete
  • Fogg slab immediately y after placing
  • Add plastic fibers

Fogging Good Fogging Bad Fogging Evaporation Retarders Curing Compound Applied to Fresh Concrete Moist Curing After the C

Concrete t HHardens d

Ad Adequate t curing i isi essential ti l

Wet burlap & plastic X

Curing Membrane

X

Ensuring Adequate Curing

  • Curing should be a separate pay item in the contract
  • Contractor should submit a curing plan
  • The various tasks - initial, intermediate &

final curing - have to made someones specific responsibility

  • Adequate inspection required
  • Problems with curing-membrane systems?
  • Proper coverage/application
  • No thermal benefit (+/-)

( /)

  • Bonding of subsequent overlay materials

Field example, Iff time allowsll Examplel where h curing was criticall on thin h

low permeability shotcrete overlay:

Specification 1/2 - in. thick 6000 psi at 28 days Less then 1500 coulombs rating (low permeability)

Bond strength of 200 psi Project Climate: frequently hot and windy conditions

Questions.

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