MECHANICAL AND PHYSICAL PERFORMANCE OF LIGHTWEIGHT CONCRETE USING WASTE PUMICE AS COARSE AGGREGATE

Abstract

The increasing demand for sustainable and lightweight construction materials has encouraged the utilization of industrial waste in concrete production. This study investigates the mechanical and physical performance of lightweight concrete produced by partially and fully replacing natural coarse aggregate with waste pumice obtained from the apparel industry. Concrete mixes were prepared with pumice replacement levels of 0%, 20%, 40%, 60%, 80%, and 100% while maintaining a constant water–cement ratio. Fresh concrete properties were evaluated through slump tests, whereas hardened concrete was assessed for dry density, self-weight, and compressive strength at curing ages of 7, 14, 21, and 28 days. The results indicate that increasing pumice content leads to a reduction in workability, density, and compressive strength due to the porous nature and high-water absorption of pumice aggregate. However, a significant reduction in self-weight was achieved, demonstrating the effectiveness of waste pumice in producing lightweight concrete. Concrete mixes containing low to moderate pumice replacement levels exhibited acceptable strength performance suitable for non-load bearing and lightweight structural applications. A strong correlation was observed between dry density and compressive strength, highlighting the predictable behavior of pumice-based concrete. The findings confirm that waste pumice can be successfully utilized as an environmentally friendly coarse aggregate alternative, contributing to sustainable construction and efficient waste management.