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

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.