ASSESSMENT OF MECHANICAL AND DURABILITY PROPERTIES OF SUSTAINABLE COMPOSITE INTERLOCKING BRICKS FOR URBAN BUILDINGS

Abstract

The mechanical and durability performance of composite interlocking bricks made with fly ash and manufactured sand (M-sand) as partial substitutes for traditional ingredients is examined in this study. Two brick sizes were assessed: 300 × 150 × 125 mm (B1) and 300 × 200 × 125 mm (B2). While durability qualities, such as initial rate of absorption (IRA) and sorptivity, were evaluated in compliance with ASTM C67 and compressive strength tests were carried out. Due to better particle packing and pozzolanic activity, the results show that replacing fly ash greatly boosts compressive strength up to an optimal level (F3), with increases of roughly 44% for B1 and 31% for B2 over the control mix. According to durability evaluation, IRA and sorptivity are significantly reduced by low to moderate fly ash substitution, suggesting improved pore structure and less capillary water absorption. Fly ash efficiently counteracts the negative effect of increased water absorption caused by greater M-sand levels.