Viability of using 100% of recycled concrete aggregates for durable solid masonry blocks

The generation of construction and demolition (C&D) waste is substantial and continues to grow annually. Despite this, only a limited portion of concrete byproducts have been repurposed using recycled concrete aggregates (RCAs) for concrete production. This study examines the feasibility of utilizing RCAs obtained from C&D waste in the production of solid masonry blocks (SMBs) for higher cement-to-aggregate (C:A) ratios. RCAs were used as replacements for natural coarse and fine aggregates in SMB manufacturing. The study assessed the influence of RCAs on the strength and durability properties of load-bearing SMBs. Results demonstrated a decline in strength and an increase in water absorption (WA) as the C:A ratio shifted from 1:6 to 1:24. Under exposure to sulfuric acid, strength losses ranged from 36.92% to 62.59%, while thermal conductivity values varied between 1.467 W/m°C and 0.371 W/m°C. Furthermore, when subjected to elevated temperatures of 200 °C to 800 °C, strength losses were observed to range from 1.87% to 65.80%. Nonetheless, SMBs with C:A ratios from 1:6 to 1:18 complied with the performance standards set by Indian guidelines. By incorporating RCAs, this research promotes sustainable construction practices, reducing the environmental impact of SMB production while enhancing their functional performance and durability.