Eco-friendly isolant composite mortars based on natural pozzolan, fly ash and plastic fibers

Civil and Environmental Engineering Laboratory (LGCE), Mohammadia School of Engineers, Mohammed V University, Rabat, Morocco

Abstract

Thermal insulation in buildings has gained significant attention recently due to the clear benefits of selecting appropriate insulation materials for energy conservation. This study presents experimental research conducted to evaluate the thermal properties of mortar based natural Moroccan pozzolan and fly ash, both of which serve as alternatives to cement powder. Unlike cement, which requires energy-intensive extraction, natural pozzolan is an abundant volcanic material, and fly ash is a powdery residu generated as a byproduct during the combustion of coal in thermal power plants. The aim of this research is to explore the potential of these materials for thermal insulation and to address the environmental concern of plastic waste management through recycling. Twenty different mortar mixes were synthesized and evaluated, with a constant 10% of fly ash and varying percentages (10%, 20%, 30%, 40%) of natural pozzolan replacing cement. Additionally, 1% of plastic fibers based on the mortar volume were included. Thermal conductivity and heat capacity of the cured mortar mixtures were measured after 7 and 14 days using a TPS1500 hot disc Analyzer, which is currently the most precise and useful method for studying thermal transport parameters. To ensure consistent conditions, all samples were preconditioned to eliminate moisture before testing. The test results indicated the potential of using plastic fibers, fly ash, and natural pozzolan as effective thermal insulation materials. These materials demonstrated reduced thermal conductivity and increased specific heat capacity, making them desirable for building applications. From an economic and environmental standpoint, incorporating them as cement substitutes for sustainable cement production in thermal insulation is the most favorable approach.