Effect of fly ash and slag on hydration heat evolution of cement

Heat evolution of Portland cement with different water to cement ratios,blending Potland cement with different additon of fly ash and slag,were studied.Strength development of Portland cement and blended cement were also investigated.The experimental results show that,after Potland cement was replaced with fly ash and slag,the total heat evolution of blended cement is lower than Portland cement.However,the reduction degree of heat evolution is not proportional with the addition of fly ash or slag.Considering the effect of the minerals on cement’s hydration heat reduction,the effect of fly ash seems better than slag.The strength results show that,under the same water to cementitious mateials ratio,the cement blended fly ash has a less strength development than that of cement blended slag in earlier age,but the former has a higher strength development rate in the later period,though the 28d strength of cement blended fly ash is less than Portland cement's.