Concrete Curing

During the hot weather we are currently enjoying it is essential that floor slabs are properly cured.

After readymix concrete is placed, a satisfactory moisture content and temperature (between 50°F and 75°F) must be maintained, a process called curing. Adequate curing is vital to quality concrete.

Curing has a strong influence on the properties of hardened  ready mix concrete such as durability, strength, watertightness, abrasion resistance, volume stability, and resistance to freezing and thawing and deicer salts. Exposed slab surfaces are especially sensitive to curing. Surface strength development can be reduced significantly when curing is defective.

Curing the readymix concrete aids the chemical reaction called hydration. Most freshly mixed concrete contains considerably more water than is required for complete hydration of the cement; however, any appreciable loss of water by evaporation or otherwise will delay or prevent hydration. If temperatures are favourable, hydration is relatively rapid the first few days after ready mix concrete is placed; retaining water during this period is important. Good curing means evaporation should be prevented or reduced.  This can easily be achieved by applying a spray on curing compound and covering with polythene membrane.