Study on the Mechanic Property of Low Heat Cement Admixing Phosphorus Slag and Fly Ash

Abstract

The strength of low heat cement mixed with phosphorus slag and fly ash in single or complex way was studied. The research results have shown that the strengths of low heat cement with fly ash or phosphorus slag at each age all decreased when increasing the mixing amount of phosphorus slag and fly ash. The decreasing extent of late strength of cement mixed with phosphorus slag slowed down significantly, but that of cement with fly ash increased obviously. Therefore, the mixing amount of phosphorus slag used as admixture in mass concrete reached up to 50%, and the late strength of cement should be used possibly. Considering the low heat for mass concrete, it is not necessary to ground the phosphorus slag too fine. The strengths of cement mixed both with phosphorus slag and fly ash were all greater than that of mortar only with phosphorus slag or fly ash. The effect of composite ratio on strength was not significant, but the late compressive strength of cement increased obviously when increasing the specific surface area of phosphorus slag.