You can make concrete cure faster through the use of concrete accelerators and by additional sources of heat and insulation where the concrete will be placed. Accelerators are added before the concrete is mixed during the batching process at the concrete plant. You can only use accelerators that have been pre-approved for your project by the Engineer of Record. Ask your building inspector what is approved as they will have it on file.

Construction workers pouring foundation
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Step 1

Talk to your building inspector and the batch manager at the concrete plant to design an accelerated mix for your concrete. Depending on the weather and materials involved in the pour (pipes, rebar) they may want to either add a calcium chloride additive or a non-chloride one.

Step 2

Cover the area you plan to pour the concrete in with thermal blankets as soon as has passed inspection and is ready for the pour. If you are preparing a very large area (such as a slab or a monolithic footing) cover the area you are working in each night (whether it is done or not) if cold weather is expected to help keep the ground temperature above freezing.

Step 3

Heat the area to be poured at least 4 hours before concrete is due to arrive. You can heat the area by uncovering it (if it will be in direct sunlight all 4 hours) or by using blown air heaters. Place the heaters so they are pumping hot air under the thermal blankets until just before you are ready to place concrete. The warmer the ground temperature is, the faster your concrete will set. If you are pouring an elevated slab, set the heaters on the floor below and the rising heat will warm the steel pans of the slab above.

Step 4

Cover the concrete as soon as it is finished. Although the concrete is still "wet" it will be firm enough to withstand the weight of the thermal blankets without the finish being damaged.