Trade Journals for the Concrete Industry

It is generally known that the fundamentals of optimum curing conditions for concrete consist of temperatures between 85°F and 120°F with the relative humidity as high as practical and some form of air circulation. Cement content also plays a part in curing and this will be addressed later in this article. For pavers, the optimum standard temperature would be 85°F to 105°F. Temperature variations can cause major problems, such as strength and color variation due to differences in the cure rates. The optimum humidity should be maintained between 85% to 95%. Saturation of the air occurs at 100% humidity and should be avoided because this will result in condensation, which can negatively affect the concrete surfaces and metallic equipment. Some form of consistent air circulation is optimum because without air movement, hot air and steam naturally rise. Exceedingly hot humid “dead spots” then develop. The negative result is that the chambers are hotter at the top while much cooler at the bottom. This can also result in uncontrolled faster cure rates at the top and much slower rates at the bottom of the chamber.