Sustainable Glass Foams From Recycled Glass and Rice Husk Ash: Thermal Insulation Performance for Ceiling Applications

ABSTRACT The intense natural resources exploitation and waste generation by the construction industry have driven the demand for more sustainable alternative materials. Thus, this study investigated the production and application of glass foams from recycled glass and rice husk ash (RHA), using calcium carbonate (CaCO ₃ ) as a foaming agent, for enhanced thermal comfort in buildings. Mixtures containing 80% recycled glass and 20% RHA were prepared with varying CaCO ₃ contents (0%–5%) and sintered at 950–1030°C to establish optimal processing conditions. The sample sintered with 2% CaCO ₃ at 1000°C exhibited the best performance: apparent density of 0.29 g/cm ³ , compressive strength of 0.81 MPa, porosity of 88.1%, and thermal conductivity of 0.1195 W/(m·K) ± 0.007. These values meet the standards for commercial glass foams and align with performances reported in the literature. To assess the practical thermal insulation effects, 20‐mm‐thick foam panels were installed as ceiling linings in a model masonry building and compared to an uninsulated control. Temperature monitoring over 8 days revealed that the foam‐lined ceiling achieved larger temperature differences, particularly during peak solar exposure, confirming its efficiency in reducing heat transfer. These results demonstrate the technical feasibility and environmental relevance of producing thermal insulation materials from recycled glass and RHA for sustainable building applications.