Placing concrete in hot weather can become troublesome. Water demand is increased and set times become faster. Here are a few hot weather concreting tips:
 
• Use of chilled water in the mix is recommended to reduce concrete temperature.
• Addition of retarding admixtures will provide additional set time.
• Dampen subgrade and wood forms to discourage water loss from the concrete.
• Start curing immediately after finishing. Avoid using clear plastic covers.
• The addition of ice will lower concrete temperature and provide additional set time.

Like hot weather, placing concrete in colder temperatures can alter the characteristics of concrete during placement. Concrete will set slower in colder temperatures.
 
• Thaw frozen ground before placing concrete. The ground can pull heat from concrete which slows down the hydration process and increases set time.
• The addition of accelerating admixtures to concrete will speed up set times.
• In cold weather hot water improves the effectiveness of accelerators.
• Do not rush form removal. Colder temperatures require more time to hydrate.

• Excessive water will lower concrete's overall strength.
• Can lower durability and increasing possibility for drying shrinkage.
• It can reduce water tightness.
• Do not add unnecessary water to concrete. Instead use additional mid-range or superplasticizer.