Effects of silica fume on heat generation of curing concrete

Currently, silica fume (SF) is quite commonly used for the production of high-performance concrete. The effects ofSF on heat generation of curing concrete, however-especially in the presence of other pozzolanic materials such as fly ash (FA) and at different watercementitious material ratios (w/cm)-are still not clearly known. To study the combined effects of SF and FA at different w/cm, concrete mixtures with SF replacement up to 10%, FA replacement up to 20%, and w/cm ranging from 0.24 to 0.40 were produced for semi-adiabatic curing tests. Heat loss compensation was applied to determine the adiabatic temperature rises of the concrete mixtures. The test results revealed that 1) the heat generation per weight of cementitious materials is generally smaller at a lower w/cm; 2) within the range of parameters studied, SF replacement would reduce the amount of heat generation but increase the rate of heat generation; and 3) compared on an equal strength basis, 5 and 10% SF replacement would reduce the amount of heat generation by approximately 10% and 20%, respectively. © 2011, American Concrete Institute. All rights reserved.link_to_OA_fulltex