Evaluation of Properties of Concrete Incorporating Fly Ash or Slag Using a Hydration Model

Abstract

Granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been used widely as mineral admixtures in normal and high-strength concrete. Because of the reaction between calcium hydroxide and fly ash or slag, the hydration of concrete containing fly ash or slag is much more complex than that of portland cement. In this paper, the production of calcium hydroxide in cement hydration and its consumption in the reaction of mineral admixtures is considered to develop a numerical model that simulates the hydration of concrete containing fly ash or slag. The properties of concrete incorporating fly ash or slag, such as the adiabatic temperature increase, chemically bound water, reaction degree of mineral admixture, and the compressive strength, are determined by the contribution of both cement hydration and the reaction of the mineral admixtures. The proposed model is verified with experimental data from concrete with different water to cement ratios and mineral admixture substitution ratios.