Experimental research was conducted to investigate the effect of the addition of calcium and magnesium oxides-based expansive agents with different compositions on the working and mechanical performances of the in-tube concrete.The results indicate that an increase in the proportion of magnesium oxide in the composite expansive agents reduces the flowability of the self-compacting in-tube concrete,while having little effects on the clearance permeability and segregation resistance.For the in-tube concrete prepared with composite expansive agents,compared to the free specimens without external constraints,the compressive strength and elastic modulus of the two-dimensional and three-dimensional external constraint specimens at different ages significantly increase.When the proportion of calcium oxide in composite expansive materials is high,this improvement effect is more obvious and can be used as a safety reserve for the design of the in-tube concrete mix proportions.
万方数据
维普
