Effects of cement and water contents on adiabatic temperature rise of concrete

Abstract

The temperature rise of concrete during curing is dependent on the mixture composition and proportions, among which the cement content should be the major factor. If the water content is relatively low, however, the cement would not fully hydrate and the water content should also have significant effects. This paper reports an experimental program aiming to investigate the combined effects of cement and water contents by measuring the adiabatic temperature rise of concrete mixtures with different mixture proportions. A newly developed semi-adiabatic curing test method with heat loss compensation applied was employed to measure the adiabatic temperature rise of the concrete mixtures. The results reveal that, for a given paste volume, the adiabatic temperature rise would be highest at a water-cement ratio (w/c) of 0.36; therefore, the adiabatic temperature rise of a higher strength concrete is not necessarily higher. Furthermore, the degree of hydration would gradually decrease as the w/c decreases. Based on these results, design charts and formulas for predicting the adiabatic temperature rise, heat generation, and degree of hydration of concrete mixtures with w/c ranging from 0.28 to 0.48 have been developed. Copyright © 2009, American Concrete Institute. All rights reserved.