Modeling the hydration of concrete incorporating fly ash or slag

Granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been widely used as mineral admixtures in normal and high strength concrete. Due to the reaction between calcium hydroxide and fly ash or slag, the hydration of concrete containing fly ash or slag is much more complex compared with 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 in order to develop a numerical model that simulates the hydration of concrete containing fly ash or slag. The heat evolution rates of fly ash- or slag-blended concrete is determined by the contribution of both cement hydration and the reaction of the mineral admixtures. The proposed model is verified through experimental data on concrete with different water-to-cement ratios and mineral admixture substitution ratios. (C) 2010 Elsevier Ltd. All rights reserved.This study was supported by the Engineering Research Center designated by the Ministry of Education & Science Technology, and Sustainable Building Research Center, Hanyang University (R11-2005-056-04003). This research was supported by a grant (06-CIT-A02: Standardization Research for Construction Materials) from Construction Infrastructure Technology Program funded by Ministry of Land, Transport and Marine Affairs