粉煤灰、矿渣对水泥水化热的影响

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

研究了不同水灰比硅酸盐水泥净浆的水化放热过程,以及用粉煤灰、矿渣粉配制成的混合水泥的水化放热过程,并研究了硅酸盐水泥和混合水泥的强度发展规律。试验结果表明:用粉煤灰、矿渣粉等量取代部分水泥,胶凝材料的水化热比硅酸盐水泥的水化热要低,但降低的幅度不完全与粉煤灰、矿渣粉的掺量成比例。单从降低胶凝材料水化热的角度看,掺粉煤灰的效果最好,掺矿渣粉的效果次之。强度试验结果表明,用粉煤灰和矿渣取代部分水泥的试件比同水灰比的水泥净浆试件的早期抗压强度小,但是后期强度增加快,从28d强度看还是不及纯水泥净浆的强度。

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 hydra- tion 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.