Influence of Steel Slag Composite Mineral Powder on the Performance of Concrete Under Different Curing Conditions
In order to study the feasibility of preparing composite admixtures from steel slag and mineral slag,composite mineral powder was prepared by jointly grinding steel slag and blast furnace slag with mass ratio of 3∶7.The influence of com-posite mineral powder on the workability and mechanical properties of concrete under different curing conditions was studied,and the hydration products were characterized.The results indicated that the composite mineral powder reduced the loss of slump flow at 1 hour by 6.9%,indicating a good slump retention effect.Under standard curing at 20℃and steam curing at 60℃,the cubic compressive strength and axial compressive strength of the mixed mineral powder concrete all exceeding the con-trol group.However,the splitting tensile strength of the concrete with composite mineral powder was slightly lower than that of the control group at all temperature curing conditions.Microscopic analysis reveals that the addition of composite mineral pow-der reduces the O/Si ratio of the hydrated calcium silicate and increases its polymerization degree.Additionally,the overall po-rosity of the cement paste decreased from 26.34%to 23.99%.Furthermore,this process promotes the formation of more hydra-tion products.The research results show that it is feasible to prepare composite mineral powder by adding appropriate amount of steel slag powder into mineral slag,and it is an effective way to realize resource utilization of steel slag and mineral slag at the same time.
steel slagcomposite mineral powdermechanical propertieshydration products
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