Recycling of steel slag aggregate in portland cement concrete: An overview

摘要

Because of the unique physical and chemical characteristics of steel slag, steel slag aggregate (SSA) has been recycled into Portland cement concrete as a substitution for natural aggregates as a sustainable and low impact design solution by reducing the use of natural resources and the landfills for disposal. This paper reviews credible achievements and challenges of SSA concrete and mainly includes four parts: SSA production, properties, treatment and performance in concrete. The performance of SSA concrete includes physical properties, mechanical properties, durability, conductivity and sustainability. Test and analysis results showed that the SSA production process mainly determines the properties of the SSA, and that SSAs with different properties require different treatments. Generally, SSA concrete can satisfy common engineering requirements and could improve concrete strength due to the improved bonding in the interfacial transition zone (ITZ). The drawbacks of the improved concrete include volume expansion due to free calcium oxides and decreased workability due to the high angularity, rough texture and water absorption of the SSA. SSA concrete showed better ecofriendliness and sustainability, as indicated by an acceptable leaching test, as well as lower total life cycle cost and environmental impact. (C) 2020 Elsevier Ltd. All rights reserved.