Modeling the hydration of concrete incorporating fly ash or slag

• Published in: Cement and concrete research 2010-07, Vol.40 (7), p.984-996
• Main Authors: Wang, Xiao-Yong, Lee, Han-Seung
• Format: Article
• Language: English
• Subjects: Admixtures; Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Concrete industry; Concretes; Concretes. Mortars. Grouts; Exact sciences and technology; Fly ash; Fly ash (D); Granulated blast-furnace slag (D); High-performance concrete (E); Hydration; Hydration (A); Materials; Minerals; Modeling (E); Other special applications (sand concrete, roller compacted concrete, heavy concrete, architectural concrete, etc.); Properties of anhydrous and hydrated cement, test methods; Slags
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2010.03.001

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.