What is the maximum time between mixing and using water above 80°?

The maximum time allowed between mixing concrete and using water above 80°F is 2 1/2 hours. This guideline is in place due to the increased rate of hydration and curing that occurs at higher temperatures. When mixed, concrete begins to set and cure, and higher temperatures can accelerate this process, leading to issues such as reduced workability and the potential for cracking if not used within the specified timeframe.

Using the concrete beyond this time limit can compromise its structural integrity, as it may start to harden before it is placed or finished, which makes it challenging to work with and can adversely affect the final quality of the concrete.

Understanding these time constraints is crucial for contractors in order to ensure the successful application of concrete, especially in warmer weather conditions.