Preparation of artificial aggregates from concrete slurry waste and waste brick masonry powder: CO2 uptake and performance evaluation

Abstract

In order to improve the reuse of solid waste generated in construction production, artificial aggregates consisting of 100% by weight of construction solid waste, including concrete slurry waste (CSW) and waste brick masonry powder (WBMP), were produced. This study investigated the possibility of mixing CSW as a substitute for commercial binder with waste brick masonry powder WBMP to prepare artificial aggregates, and studied the effects of sedimentation time of CSW and aggregate curing methods on the properties of artificial aggregates. The results showed that sedimentation time had an important influence on the properties of CSW and granulation effect of artificial aggregates, Long sedimentation time reduced the potential activity of CSW and its dispersion in the artificial aggregate matrix, which had a negative impact on the compressive strength and other properties of artificial aggregates. In addition, the artificial aggregates prepared using the combined air-CO2 curing method (AC + CC) had the lowest water absorption and the highest aggregate crushing strength. The artificial aggregate particles sequestered approximately 3% of CO2 under CO2 curing, which makes the CO2 curing method a sustainable curing method with both engineering and environmental benefits.