Cooling concerns for concrete
Cooling concerns for concrete
(OP)
Hey - We've got a retaining wall that will be 8' thick (36' high, ~300' long) and will be constructed in New Orleans. Is this thick enough to worry about cooling in the summer heat in that area? I am fairly certain it would not require cooling pipes or other involved measures, but does it warrant suggesting/specifying construction in cooler months? Thanks






RE: Cooling concerns for concrete
www.SlideRuleEra.net![[idea] idea](https://www.tipmaster.com/images/idea.gif)
www.VacuumTubeEra.net
RE: Cooling concerns for concrete
RE: Cooling concerns for concrete
You will want to keep the exterior surfaces warm untill the interior cools sufficiently. You may want to think about using concrete blankets to keep the exterior surface of the concrete warm. Though this sounds like it might be pretty tough given the size of the wall.
See ACI 207.1 for some additional info, and talk with a concrete supplier and contractor who have done 'mass' concrete pours.
RE: Cooling concerns for concrete
RE: Cooling concerns for concrete
RE: Cooling concerns for concrete
The problem with casting during the summer is that the concrete should be placed at as cool a temperature as possible. You should check with the concrete batching plant what measures they have available including reducing the heat of the aggregates, the use of ice or chilled water and peferably PFA in replacement for some OPC .
Instead of casting in cooler months you could cast at night, or preferably very early morning when the aggregates are at their coolest and the sun isn't heating up the drums on the truck mixers.
RE: Cooling concerns for concrete
RE: Cooling concerns for concrete
you don't need the heat to escape. You need to limit the heat differential between the centre of the pour and the surface.
There are many ways to achieve this including reducing the temperature of the concrete at the time of casting and keeping the formwork in position longer.
For "thinner" pours, which you mention, there should not be a problem as it is a mass of concrete (i.e a large quantity of cement) which generates the heat of hydration which may result in cracking.
RE: Cooling concerns for concrete
They are ACI 305R-99 and ACI 305.1-06.
They provide some guidance into the concrete aspects.
The realatively narrow temperature variations (with relatively warm uniform temperatures) lend a certain amount on consistancy with aggregates, that really do not cool in the evenings.
Spray on curing componds hold in moisture and do not offer cooling to a thin 8" concrete wall.
If you are concerned about the concrete temperatures during and after placement, use cold mixing water, fly ash and slow curing cement. There is a required chemical reaction when concrete hydrates and firtunately you do not have a mass concrete problem or overheating, but a constructability situation that can be controlled.
You are not going to pour the entire length at once, so look to the joints to mainatain the integrity you desire.
Dick
RE: Cooling concerns for concrete
The wall is 8' think not 8". Heat of hydration is a concern which needs to be looked at.
RE: Cooling concerns for concrete