大掺量高钙粉煤灰碾压混凝土安定性控制与性能研究

Research on volume stability control and the performance of RCC with large volume of high calcium fly-ash

采用消解、粉磨等技术措施解决大掺量(60%)高钙粉煤灰水泥浆体体积安定性问题。试验发现,大掺量高钙粉煤灰碾压混凝土抗压强度、轴拉强度和弹性模量比普通粉煤灰混凝土提高10%,极限抗拉应变两者相当。28d、90d两者均表现为收缩,但前者干缩变形和自身体积变形只有后者的50%,这表明高钙粉煤灰具有补偿收缩的作用。研究证明,大掺量高钙粉煤灰碾压混凝土性能满足水工大体积混凝土的技术要求,且技术经济效益比普通粉煤灰混凝土优越。

The volume stability problem of the cement paste with large amount （above 60 % ） of high calcium fly-ash is solved by the measures of the slaking and milling. The tests indicate that the axial compressive strength, tensile strength and the elastic module of the RCC with large amount of high calcium fly-ash increase about 10% than that of the common fly-ash concrete, while their limited tensile strains are equivalent. The shrinkage-compensating action of the high calcium fly-ash is proved by the facts that its dry shrinkage and self-volume deformation at both 28d and 90d age of concrete is only 50% of that of the commoun fly-ash concrete. It proves that the performance of the RCC with large amount of high calcium fly-ash may satisfy the technique requirements of hydraulic mass concrete, its technique and economic benefits are predominant than that of the common fly-ash concrete.