Reduction of CO2 Emissions and Energy Consumption through Cement Minimization in Cement-Plastic Composite Masonry Blocks

Abstract

The construction sector is one of the largest consumers of energy and raw materials and is responsible for a substantial share of global greenhouse gas emissions. Cement production is especially important in this context because it requires high-temperature processing and releases carbon dioxide both through fuel combustion and limestone calcination. The present paper evaluates the potential reduction of CO2 emissions and energy consumption achieved through cement minimization in cement-plastic composite masonry blocks incorporating recycled plastic waste and alternative mineral fillers. The proposed approach combines material substitution, lightweight composite design and improved thermal performance of building envelopes. Experimental data obtained for recycled plastic-mineral composite blocks indicate that an optimized composition can reduce material density and thermal conductivity while maintaining compressive strength suitable for lightweight masonry applications. A simplified environmental assessment is used to estimate cement-related CO2 savings and operational energy benefits associated with lower heat transfer through wall elements. The results demonstrate that reducing cement content by approximately 30-35% and incorporating recycled plastic waste can contribute to lower embodied emissions, improved resource efficiency and reduced building energy demand. The developed concept supports circular economy principles and provides a practical pathway for low-carbon construction materials in regions where plastic waste accumulation and energy efficiency remain important environmental challenges.