Developing thermal insulation concrete with enhanced mechanical strength using belitic calcium sulfoaluminate cement and wood chips

Mixing forest industrial by-products, wood chips, with cement to produce thermal insulation concrete can help reduce energy consumption associated with temperature control in buildings. However, wood chips-based concrete usually has low strength due to the incompatibility between wood chips and the widely used ordinary Portland cement (OPC). To address this issue, this study explored using belitic calcium sulfoaluminate (BCSA) cement to replace OPC to enhance the mechanical performance of wood chips-based thermal insulation concrete. The investigation includes the analysis of thermal properties, physical properties, unconfined compressive strength (UCS), hydration reaction, and carbon footprint analysis for mixtures. The findings show that the wood chips concrete achieved an average oven-dry bulk density of 803 kg/m 3 and thermal conductivity of 0.237 W/mK, establishing it as a lightweight thermal insulation concrete. In addition, the UCS results highlight BCSA cement's superior compatibility with wood chips. When replacing OPC with BCSA cement, the one-day unconfined compressive strength (UCS) of wood chips concrete increased from 0.7 ± 0.0 MPa to 5.1 ± 0.0 MPa, and the 28-day UCS increased from 4.3 ± 0.2 MPa to 8.0 ± 0.4 MPa. The carbon footprint analysis showed that utilizing BCSA cement and wood chips to develop thermal insulation concrete can result in a negative net carbon footprint of −34 kg CO 2 per tonne of mixture. The results show that replacing OPC with BCSA cement in wood chips concrete can achieve higher mechanical performance, excellent thermal insulation properties, and a negative carbon footprint. • Thermal insulation concrete was developed with belitic calcium sulfoaluminate (BCSA) cement and wood chips. • BCSA cement significantly increased the strength of wood chips-based concrete. • BCSA cement showed better compatibility with wood chips than Portland cement. • Concrete developed with BCSA cement and wood chips has a negative carbon footprint.