Hot Weather Concreting

As the weather heats up it’s time to introduce hot-weather practices during concrete placement. Such practices typically involve using cooling mists, moist curing, retarding admixtures, low temperature mix water and even ice.

Hot-weather practices are generally necessary whenever temperatures exceed 90°F or humidity drops below 25%, or winds exceed 25 mph. Conditions can also combine to require hot-weather practices at lower temperatures and wind-speed, e.g., 80°F and 15 mph winds. Controlling the concrete temperature is a critical factor and shading placements from direct solar heating is also helpful.

Curing agents are often applied to control plastic shrinkage cracking. To work effectively, curing agents should be colored, be applied as a fine mist, and used while the concrete surface is still damp (bleeding).

Refer to ACI 305.R-10 and NRMCA CIP 12 for additional information.

Learn more: aci.org; nrmca.org; precast.org