Effect of Washing Process on the Performance of Coarse and Fine Recycled Aggregates

Large quantities of Construction and Demolition Waste (C&DW) are produced every year, and recycling has become the preferred method for managing concrete waste. In this context, studying the influence of the production process on the properties of recycled concrete aggregates (RCA) is an important step toward a more circular construction industry. In this study, the influence of an innovative multi-step water washing treatment on RCA and Recycled Mixed Aggregates (RMA) is investigated. Washed and unwashed recycled aggregates, produced from waste originating from a single demolition project, were characterized. The particle size distribution, Hardened Cement Paste Content (HCPC), water absorption, resistance to fragmentation, and morphology of the recycled aggregates were measured and analyzed. The results show that the water washing treatment significantly improves the quality of the aggregates by reducing fine content, floating contaminants, HCPC, and water absorption. This effect is more pronounced for RCA than for RMA