MULTI-COMPONENT MODEL FOR HYDRATION HEAT OF PORTLAND CEMENT

Abstract

In checking the durability of a concrete structure, effective material design depends on being able to represent the characteristics of the materials being used in generalized form. In particular, the analysis of temperature stress requires a hydration heat model of the cement which is applicable to any given conditions. This study proposes a model of hydration heating that describes the hydration reactions of cement in terms of the reactions of individual mineral components of the cement and expresses the differences between various types of Portland cement as differences in mineral composition. The rate of hydration heat generation for each mineral component is expressed using two material functions: a reference heat generation rate at constant temperature and the thermal activity. Taking into account the temperature dependence of individual mineral component's reactions, the exothermic behavior of the cement as a whole during hydration is quantified for any given temperature history. The proposed model has been verified through analysis of adiabatic and semi-adiabatic temperature rises.