摘要
本文在混凝土可泵性指标研究成果的基础上,主要结合高层建筑泵送施工的条件,探讨了粉煤灰对混凝土拌合物流动性、稳定性及可泵性的影响.试验结果表明,粉煤灰对混凝土可泵性的影响主要是提高稳定性。在掺减水剂的混凝土中,掺加适量粉煤灰可在保持流动性基本不变的同时,明显提高稳定性。这是掺粉煤灰能改善混凝土可泵性的主要原因.
In this paper, the effects of addition of fly ash on flowability, bleeding and pumpability of concrete mixtures used for highrise construction by pumping were investigated. The main effect of fly ash was found to be the reduction of bleeding rate of concrete mixtures. Thus, addition of a proper amount of fly ash to the mixture with water-reducer could improve the stability of the concrete mixture, keeping the slump value basically unchanged. The main mechanism of the effect of addition of fly ash, widely used in pumping concrete mixture in Shanghai, was then explained.
