Enhanced Thermo-Physical Properties of Gypsum Composites Using Olive Pomace Waste Reinforcement

Today, the construction sector consumes 30-40% of the world's total energy and contributes one-third of total greenhouse gas emissions. Consequently, the development of new eco-friendly building materials with improved properties is becoming increasingly important. Olive pomace waste is released into the environment, which has a negative impact on it. Recycling this olive pomace waste as an alternative raw material in the construction industry can protect the environment and at the same time reduce the additional costs of managing and disposing of this waste for local authorities. It is an environmentally friendly and sustainable solution to waste recycling. This study investigated the effect of adding olive pomace (OP) to building materials. Four proportions of this additive (4%, 8%, 12% and 16%) were used. Physical, thermal properties (conductivity and diffusivity) as well as mechanical properties (compressive and flexural strength) of the composites were carried out. The traditional gypsum -based composites had a thermal conductivity of 0.478 W.m-1.K-1, while the composites of gypsum with additive show an interesting thermal conductivity of 0.390 W.m-1.K-1 for a percentage of 16% (OP16) with a reduction rate of 22.56%, and mechanical properties lower than those of the reference gypsum -based composite but in accordance with the standard EN 133279-1, with compressive strength of almost 4.10MPa for a percentage of 16% (OP16), and flexural strength equal to 2MPa. This is due to the increase in porosity as indicated by the microstructure of the composites. We also tested water absorption by capillary action for each specimen, and found that this coefficient increased with increasing percentage of waste.