Study on the Properties of High-Performance Ground Iron and Steel Slag Based on the Uniform Design

Ground iron and steel slag with excellent performance was prepared using the uniform test design. The influence of the fineness and content of steel slag powder on the fluidity and strength of the powder mortar was studied, the regression equations of fluidity and compression strength of different ages are derived, and the contour map is drawn. Based on the optimized composition, the bleeding and dry shrinkage properties and their application in slag concrete are evaluated; the results are compared with ground granulated blast furnace slag powder. The correlation coefficient between fluidity and compression strength of the mortar is more than 0.99, and the predicted value is in good agreement with the measured value, and the average relative error is less than 2%. Regression and isogram analyses show that an increase in the slag fineness and a reduction in its the content contribute to the improvement of the cementiting slag activity. The adequate composition is: steel slag (specific surface area: 520 m(2)/kg): 20%; blast furnace slag: 80%. Appropriate slag amount can significantly reduce the bleeding and dry shrinkage properties of mortar and optimize the microstructure of the interface transition zone of the concrete aggregate.