In countries where the climate is favorable, green blocks are moist cured at normal temperature of 20℃to 37℃(as in the south of China), this type of curing which at 4 days would normally give 40% of its ultimate strength, initially, green blocks should be placed in a shaded area or enclosed chambers for about 8-12 hous(depends on relative weather condition i.e temperature,humidity etc) After that, the blocks can be transported to an assembly yard for further curing for about 28 days to reach 99% of its maximum strength. For optimal final products, the fresh blocks need to be sprinkled daily, for the first 7 days to maintain the moisture content for higher reactivity of cement with sand.
Length of curing
|Type of Portland Cement||Curing times||Concrete Surface Temperature|
|Type I||5 days||70 ºF or higher|
|Type II||3 days||5 ºF|
|Other than Type I or Type II||7 days||70ºF|