高流动性自密实混凝土在地铁工程中的应用研究

Research on Application Technology of High Fluidity Self-compacting Concrete in Metro Engineering

由于高流动性混凝土工作性影响因素方面研究的不足,限制了其在地铁工程中的大规模应用,为解决这一问题,文中结合实体工程项目,调整减水剂成分及掺量、砂率、水灰比和粉煤灰掺量,研究其影响。经研究可知,胶材用量不变的情况下,工作性能随砂率的上升先改善后变差;合理砂率对流态混凝土的扩展时间T_(500)有着显著影响;最终扩展度会随水灰比的上升逐渐增加,其离析率变化情况与之相反;粉煤灰最佳掺量的质量分数在20%~30%之间。

Due to the insufficiency research on the influencing factors of workability of high fluidity concrete,its extensive application in the metro engineering is limited.To solve this problem,the composition and content of water reducing agent,sand ratio,water-cement ratio and fly ash content is adjusted to study their effects by combining the practical engineering project.The results show thatthe performance of high flow self-compacting concrete improves first and then becomes worse with the increase of sand percentage when the amount of rubber material is constant,and reasonable sand ratio has a significant effect on the expansion time T500 of fluidized concrete.The final expansion degree increases with the increase of water cement ratio,and the change of segregation rate is opposite.The optimum mass fraction of fly ash is between 20%and 30%.