Utilization of steel slag in concrete as coarse aggregate

Abstract

This study has been conducted to explore the possibility of utilization of steel slag in concrete as coarse aggregate. After collection of steel slag aggregate from a local steel manufacturing company, the steel slag aggregate was separated into lightweight (SL), heavyweight (SH), and mixed (SM) slag aggregates. The aggregates were tested for different physical properties as well as mechanical properties by preparing cylindrical concrete specimens (100 mm by 200 mm) with different W/C ratios, cement contents, and sand to aggregate volume ratios. Total eleven cases for slag aggregates and five cases for brick aggregates were investigated. The concrete specimens were tested at 7, 28, 60 and 90 days. Also, ultrasonic pulse velocity (UPV) test was conducted prior to crushing of the specimens for evaluation of compressive and tensile strengths. For comparison, similar investigations were also carried out on brick aggregate commonly used in Bangladesh. Experimental results show that slag aggregates absorb less water compared to the brick aggregates. The compressive strength of concrete made with mixed slag aggregate is similar or better than that of concrete made with brick aggregate. Concrete made with heavyweight slag aggregate gives more compressive strength than other aggregates. Relationships between compressive strength and modulus of elasticity of concrete, compressive strength and tensile strength of concrete are proposed for different slag aggregates.