Experimental and theoretical investigation of thermal properties of natural soil based geopolymer composites

Abstract

Abstract Geopolymer composites have found numerous thermal management applications in the construction industry due to their low thermal conductivity. In this work, geopolymer foams were produced using natural soil with varying fractions of sodium silicate solution. The extent of geopolymerization was evaluated based on qualitative and X-ray diffraction analyses. Scanning electron microscopy was performed to characterize the shape morphology. Thermal properties were measured using a hot disk analyzer. The effect of shape morphology and porosity on the thermal conductivity of the composites was discussed using several theoretical models. Yan- He, Hamilton-Crosser and geometric mean models showed good comparison with experimental observations. It was revealed that the geopolymerization reactions affect the porosity level, which, in turn, influences the effective thermal conductivity of the medium.