Performance evaluation of concrete comprising sugarcane bagasse ash and recycled polyethylene terephthalate

Concrete production faces challenges due to the depletion of natural sand and the need for more sustainable practices. This study investigates the use of sugarcane bagasse ash (SCBA) and recycled polyethylene terephthalate (RPET) as partial replacements for cement and sand, respectively. SCBA was tested as a 5%, 10%, and 15% replacement by weight of cement, while RPET was used as a 5%, 10%, 15%, and 20% substitute for sand by volume. Concrete samples were cured in water for 7, 28, and 56 days. The mix with 5% SCBA and 10% RPET showed comparable compressive strength to conventional concrete and improved split tensile strength by 1.2% and 11.61% at 28 and 56 days, respectively. The compressive strength-to-weight ratio of this blend was less than 3% lower than conventional concrete. This combination also maintained similar water absorption and fire resistance characteristics. These results suggest that 5% SCBA and 10% RPET are effective in enhancing the sustainability of concrete while maintaining structural performance, contributing to more environmentally friendly construction practices.