A maturity approach to the rate of heat evolution in concrete

Abstract

This paper discusses the use of the concept of maturity as a means of combining the effects of time and temperature in describing the rate of heat evolution from hydrating cement in concrete. The proposed maturity approach allows the rate of heat evolution determined from an adiabatic test to be expressed in a form which is independent of the starting temperature of the test. This relationship can then be directly used in a time–temperature prediction model that requires a solution of the Fourier equation for heat flow. The results of an experimental study aimed at assessing the suitability of both the Arrhenius and Nurse–Saul maturity relationships is also presented. Three adiabatic calorimeter tests were conducted on each of two concrete mixtures but starting at different temperatures. The results confirm the suitability of this approach and indicate that, of the two maturity relationships assessed, the Arrhenius maturity relationship is the more suitable in this application.