Trade Journals for the Concrete Industry

This study evaluates fine recycled aggregates (FRA) from raw construction and demolition waste (C&DW) for use in concrete product manufacture, focusing on quality control. In South Africa, waste separation at the source is uncommon and the heterogeneous nature of C&DW presents challenges to maintaining consistent quality in concrete production. Different FRA batches from a single source over six months were used to replace natural aggregates at 0%, 25%, and 50% with w/c ratios of 0.45 and 0.6. The results indicate that while FRA generally meets standard specifications, adhered mortar on the surface of recycled aggregates increases water absorption and reduces density, impacting concrete performance. Based on the results, FRA is recommended for non-structural concrete applications, such as bricks and blocks, contributing to sustainable construction by recycling C&DW into low-strength concrete products.