Sooner or later each summer, some contractors will be in for a surprise. Their concrete will be acting in ways they didn't expect, losing slump rapidly and setting too fast. On top of that the strength may be low. Experienced contractors prepare ahead of time to avoid these unexpected but unnecessary troubles. Here are some of the precautions they take:

  1. Cool the ingredients prior to batching.
  2. Avoid mixing concrete for a prolonged time.
  3. Cool the concrete during placing and curing.
  4. Treat test cylinders with respect.


If the mixing and curing temperature is about 18 degrees Fahrenheit higher than usual it will make the strength about 10 percent lower. It is also likely to require more mixing water for the same slump, and this is enough to lower the strength about another 10 percent.