Research on thermal performance of eco-friendly self-insulating composite wall panels

Abstract Under the guidance of the dual-carbon strategy, improving the resource utilization efficiency of construction waste is of great practical significance and engineering value. This paper developed an eco-friendly self-insulating composite wall panels (CWP) using waste soil and recycled aggregate as the main raw materials. The optimal mix ratio for the insulation core of ceramsite foamed clay and the mix ratio for the outer recycled concrete were determined. Two specimens of CWP with insulation layer thicknesses of 120mm and 100mm were fabricated, and their thermal performance was tested using the heat box-heat flow meter method. The thermal performance of the full-scale eco-friendly self-insulating CWP was analyzed using ABAQUS finite element software, revealing the effects of insulation layer thickness, thermal conductivity, and rib length retained ratio (RLRR) on the heat transfer performance of the wall panel. A theoretical calculation method for the heat transfer coefficient of ribbed composite wall panels was proposed. The results indicated that the optimized insulation core had a dry density of 530.9 kg/m³, a thermal conductivity of 0.1022 W/(m•K), and a compressive strength of 0.464 MPa, exhibiting excellent lightweight and thermal insulation properties; The recycled concrete produced had a thermal conductivity as low as 0.5529 W/(m•K) and a compressive strength of 21.27 MPa. The heat transfer coefficients of wall panels with insulation layer thicknesses of 120mm and 100mm were 0.85 W/(m²•K) and 0.98 W/(m²•K), respectively, meeting energy-saving standards for hot-summer and cold-winter regions, with no risk of condensation on the inner surface of the wall panel. With the increase in insulation layer thickness, the thermal conductivity of the wall panels decreased significantly. An increase in the RLRR intensified the thermal bridge effect. By adjusting core thickness, the thermal conductivity of the core, and RLRR, coordinated optimization of CWP structural and thermal performance can be achieved.