The impact of air gap and two types of additives on the thermal insulation of building materials

Abstract The energy consumption of a structure is significantly influenced by the properties of its envelope. The thermal efficiency of external walls is a crucial element in enhancing energy efficiency within the construction industry and mitigating greenhouse gas emissions. Thermal insulation is unequivocally one of the most effective methods to diminish energy usage for winter heating and summer cooling. This research examines both experimentally and numerically the thermal insulation properties of two prevalent building materials in Iraq: sandwich panels and concrete. The thermal conductivity of many commercial sandwich panel samples, including Al-Sabah, ARI-HAN, Assad, and Milano, has been analyzed as construction materials. The findings indicate that the thermal conductivity of the Assad panel surpasses that of the other samples, at 0.121489366 W m −1 ·k. An upgrade was conducted on the thermal insulation of the sample exhibiting lower insulation (greater thermal conductivity) by incorporating one, two, and three rows of 8 mm diameter air cavities, with a 10 mm spacing between each cavity. Secondly, the thermal conductivity of concrete without additives and with 5, 10, 15, and 20% frond ash and volcanic ash was tested. The experimental results of the sandwich panel indicate an increasing percentage of thermal insulation for one row, two rows, and three rows (9, 22, and 33%, respectively). The findings indicated an enhancement in the thermal insulation from 9 to 16% for frond ash and from 11 to 30% volcanic ash. The compressive strength of concrete with frond ash increased by 1.3 of concrete without an additive following the incorporation of the components.