Heat Generation of Curing Fly Ash Concrete at Different w/cm

Abstract

It is well known that the heat generation of curing concrete is higher when the cement content is higher and lower when part of cement is replaced by fly ash (FA). As the water-cementitious material ratio (w/cm) would affect the proportions of cementitious materials that would react with water, however, it should also have certain effect. To study the combined effects of FA replacement and w/cm, the temperature rises of concrete mixtures with FA replacement ratios ranging from 0-40% and w/cm ranging from 0.24-0.48 were tested. Heat loss compensation was applied to obtain the adiabatic temperature increases of the concrete mixtures. The results revealed that the heat generation is lower at a lower w/cm, and the reduction in heat generation due to FA replacement is greater at a higher w/cm. At the same required strength, however, the effectiveness of FA replacement in reducing heat generation is higher at a higher strength level when the w/cm is relatively low.