Thermal and acoustic performance of solid waste incorporated cement based composites: an analytical review

Abstract

Extensive reviews have been conducted on the mechanical, structural, and durability properties of cementitious composites incorporating waste materials. However, a significant knowledge gap exists regarding a comprehensive analysis of their thermal insulation and sound absorption properties. This review seeks to bridge that gap by examining the effects of various waste materials, such as rubber, plastic, glass, ceramic, wood, construction waste, and bio-waste, on these properties in concrete. Incorporating these waste materials improves thermal insulation and sound absorption mainly by increasing porosity and creating interconnected micro and macro pores, leveraging the waste materials’ inherent high porosity and low density. Key findings from the review include a 77% reduction in thermal conductivity with 45% volume replacement of dry materials with plastic compared to control concrete. In addition, maximum sound absorption of 60% at 2000 Hz was achieved with a combination of fly ash and rubber at 30% weight replacement of coarse aggregate. Optimizing the thermal insulation and sound absorption properties of concrete is critically dependent on effective particle size, as it directly influences the concrete’s pore structure. Finer rubber particles (0.1–4 mm) significantly enhance thermal insulation by reducing thermal conductivity to 0.28 W/mK, compared to 0.44 W/mK for coarser particles (5–10 mm). In contrast, coarser particles improve sound absorption, achieving a peak absorption of 32% at 1000 Hz, compared to 27% for finer particles. This dual optimization strategy demonstrates the potential for tailored particle sizes to improve the necessary properties of concrete. The review also outlines future research directions and practical applications, highlighting the potential of recyclable waste materials in the building construction and insulation industry.