A Study on the Thermal Conductivity Properties of Cellular Lightweight Concrete Blocks Mixed with Plastic Waste

Abstract

This study investigates the incorporation of polyethylene terephthalate (PET) plastic waste into cellular lightweight concrete blocks, with the objectives to examine (1) compressive strength, (2) density, and (3) thermal conductivity of cellular lightweight concrete incorporating PET waste. The results revealed that compressive strength decreased with increasing amounts of PET waste. The highest compressive strength was observed in the control mix (0% PET), while the compressive strengths for mixtures containing 20%, 40%, and 60% PET waste showed a successive decrease. Moreover, the compressive strengths were lower than the minimum standard specified by TIS 2601-2013. This reduction was attributed to the weakened bonding among aggregates. Additionally, the density of the concrete blocks decreased as the proportion of PET waste increased, with the 60% PET mixture exhibiting the lowest density. This is due to the lower density of PET compared to conventional aggregates, resulting in lighter specimens, which may be advantageous for construction projects requiring structural weight reduction. Furthermore, the thermal conductivity decreased as the PET waste content increased, with the 60% PET mixture providing the lowest thermal conductivity. These findings demonstrate the potential of PET waste-incorporated cellular lightweight concrete as an effective thermal insulation material for building walls. Therefore, this material is suitable for use in non-load-bearing wall applications and presents an alternative option for the development of construction materials with specialized properties tailored to diverse architectural requirements.