EFFECTS OF HIGH TEMPERATURES ON THE PROPERTIES OF FRESH CONCRETE

The effects of high temperature on the properties of fresh concrete and the mechanism of the setting of cement paste and concrete are described. The undesirable effects of high temperature on fresh concrete mentioned include increased water demand, increased rate of slump loss, increased rate of setting, and increased tendency for plastic shrinkage cracking. This is followed by a discussion of the mehtods to minimize the above effects; the roles of water-reducing and set-retarding admixtures, superplasticizers, and retempering of concrete are described. (Author)