Modeling the thermal conductivity of the ground granulated blast furnace slag-based foam geopolymer based on its multi-scale pore structure

Abstract

The pore structure plays a crucial role in the thermal conductivity of porous materials. Foam geopolymers, with their inherently low thermal conductivity, show strong potential for building insulation. However, a quantitative model correlating their multi-scale pore structure with thermal conductivity is still lacking. This study prepared six types of ground granulated blast furnace slag-based foam geopolymers to investigate this relationship. The results confirm their effectiveness as thermal insulators, achieving a minimum thermal conductivity of 0.094 W/m·K. A detailed analysis of their multi-scale pore structure was conducted, treating micropores and macropores separately to capture their distinct effects. Based on experimental data and theoretical derivation, a thermal conductivity model was developed, introducing macropore shape as an innovative variable. The model demonstrated high accuracy in predicting thermal conductivity.