Experimental Research on Mechanical Properties of Concrete Mixed with Slag and Aeolian Sand

In order to study the influence of slag and aeolian sand on the strength of concrete, a batch of single-mixed slag (replacement ratios from 0% to 30%) was designed to replace cement of equal masses in initial concrete and single-mixed aeolian sand (replacement ratios from 0% to 30%) to substitute river sand of equal masses in initial concrete, and mixed slag (a replacement ratio of 30%) and mixed aeolian sand (replacement ratios from 0% to 30%) in the same time to respectively substitute the equal masses of cement and river sand, and the compressive strength, splitting strength, flexural strength and pull-out tests were conducted to compare the effect of slag and aeolian sand on concrete in different replacement ratios. Scanning electron microscope (SEM) was used to analyze the concrete microstructure. The results showed that when slag and aeolian sand were mixed separately, the effect of aeolian sand on the improvement of the compressive strength and splitting strength of concrete was more significant than that of slag, but with the increase of the replacement ratio of slag or aeolian sand, the flexural strength of concrete decreased. The combined action of slag and aeolian sand could effectively improve the compressive strength, splitting strength of concrete and the bonding strength between concrete and steel bars. When the replacement ratios of slag and aeolian sand were 30%, the mechanical property of concrete was better.