高性能粉煤灰混凝土工作性能与收缩性能研究

摘要

在对不同粉煤灰掺量混凝土的坍落度、扩展度和坍落度经时损失测定的基础上,研究了粉煤灰掺量为50%和60%的混凝土在不同水胶比条件下的收缩性能。研究结果表明：与基准混凝土相比,粉煤灰可以有效提高混凝土的流动性,降低其坍落度经时损失;对于煤灰掺量为50%和60%的混凝土,其初期收缩较快,后期收缩较为缓慢;尽管粉煤灰可以改善混凝土的收缩性能,但对其收缩变化趋势影响不大。%In this paper,based on the measure of slump,slump flow and gradual loss of fly ash concrete,the shrinkage properties of concretes with fly ash contents of 50% and 60% were investigated at different in water-binder ratio.The results show that fly ash can effectively increase the fluidity of concrete and decrease its gradual loss,compared with the concrete without fly ash,the initial shrinkages of the concretes with fly ash contents of 50% and 60% increase so rapidly and their later shrinkages relatively slowly increase.Moreover,fly ash can certainly improve their shrinkage properties,but almost have no effect on the tendency of shrinkage.