There’s nothing better than a big glass of water filled with ice on a hot summer day. Concrete may feel the same way, also.
Weather is one of the most important factors during any concrete placement and when placed in hot weather, quality can be greatly diminished if the proper precautions are not taken. The Portland Cement Association estimates that, for every 20 degrees Fahrenheit of increased ambient temperature, the curing time of concrete can be reduced by as much as half. This decreased amount of work-ability time can put stress on a crew to complete the finishing work before it hardens and increase the risk of cracking. The PCA also suggests that steps be taken to reduce hot weather effects when ambient temperatures rise above 77 degrees Fahrenheit and especially after temperatures reach 90 degrees.
One way crews are keeping the temperature of their concrete cooler on hot days is to use ice. In fact, construction crews are using so much ice in Charlotte, North Carolina, that it’s becoming local business Zippy Ice’s fastest growing sector, as well as their highest source of revenue, according to a TWC News story. The ice they produce is 22 degrees, which is sure to be able to bring the temperature of a concrete mix down to more manageable levels. Before dropping chucks of ice into your mix, however, it’s worth noting that ASTM C1602 requires that ice be completely melted by the time mixing is complete. Depending on the amount of ice used and the ambient temperature, it may be better to purchase larger or smaller pieces of ice, or wait until it’s melted before adding it to the mixer. You should also enlist the help of an engineer to help you determine the amount of ice needed.
