Development of green cement from solid wastes

Abstract

In this study, a green cement (GC) was prepared primarily using incineration bottom ash (IBA) and recycled concrete fine (RCF) at a low clinkering temperature of 1200ºC. This clinker mainly consisted of belite (C2S) and rankinite (C3S2) and demonstrated the versatility of strong carbonation reactivity and latent hydraulicity. Compared to the commercial benchmark - ordinary Portland cement - after being subjected to carbonation curing, GC exhibited superior macro- and micro-mechanical performance due to the densified microstructure. In addition to rapid strength gain at an early age, the carbonated GC also exhibited a substantial increase in strength at later ages and eventually recorded a high strength of 86.4 MPa. Furthermore, the leaching behaviour assessment on commonly regulated heavy metals validated the environmental stability of this waste-derived binder. The development of this sustainable cement has good potential to divert solid wastes otherwise destined for landfill sites to high-value-added construction products.