Performance of concrete made with steel slag and waste glass

• Waste glass can increase the workability of steel slag concrete.
• Adding waste glass to steel slag concrete can limit the density increase.
• Low quality coarse steel slag can have a detrimental effect on concrete.
• Steel slag and waste glass can improve the fire resistance of concrete.

This paper presents a series of tests on concrete made with steel slag and waste glass. Reference tests were also conducted on limestone aggregate concrete and lightweight aggregate concrete. The material properties of different types of concrete were evaluated by assessing slump, density, modulus of elasticity, compressive strength and flexural strength. Fire tests were conducted on plain concrete columns with a diameter of 250 mm and a height of 800 mm to investigate the influence of aggregate type on the fire performance. The research results demonstrate that it is feasible to replace all coarse aggregate or partial fine aggregate with steel slag and/or waste glass. Waste glass can increase the workability and reduce the density of steel slag concrete. Compared with the control limestone aggregate concrete, the concrete made with steel slag had comparable or even higher compressive strength, flexural strength and modulus of elasticity. When coarse aggregate was replaced by up to 17.5% waste glass, only minor influence on concrete mechanical properties was observed. Due to their excellent thermal and/or mechanical properties, steel slag and waste glass demonstrated the ability to improve the fire resistance of concrete.