Experimental analysis of thermal insulation performance in concrete blocks integrated with recycled rubber crumbs

Abstract

This paper presents an experimental investigation of thermal insulation in rubberized concrete blocks, where the fine aggregate size was replaced by rubber crumbs at varying ratios (0%, 10%, 20%, 30%, 40%, and 50%). The rubber crumbs used in this study ranged in size from 0-1mm, 1-3mm, and 2-4mm. A mixing ratio of 4:2:1 was employed, and simulated solar energy at a rate of 500 W/m2 was applied to the outer surface of the test samples. Heat flux sensors were installed on both the internal and external surfaces to measure transient heat flux through the samples, while K-type sensors were used to measure surface temperatures. The samples were placed in an adiabatic room with an open front side for testing. The results of the study indicate that the addition of rubber crumbs to the concrete mixture improves thermal insulation properties, as evidenced by a decrease in thermal conductivity corresponding to the volumetric substitution ratio of rubber crumbs with the volume of sand in the sample. Particularly, a 50% incorporation of rubber crumbs led to a substantial 76.2% reduction in thermal conductivity, indicating the effective thermal insulation provided by rubberized concrete. These findings hold significant implications for energy conservation within the building sector, where the use of rubberized concrete can contribute to improved energy efficiency and reduced heat transfer.