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

Abstract

The cement industry is responsible for approximately 7–8% of global anthropogenic CO₂ emissions, primarily due to high-temperature clinker production and intensive energy consumption. Reducing cement content in construction materials represents a critical pathway toward sustainable development. This study evaluates the environmental benefits of lightweight masonry blocks produced with reduced cement content and recycled plastic aggregates. By replacing a significant portion of mineral aggregates and minimizing cement dosage to approximately 10–20%, the proposed composite block achieves notable reductions in embodied energy and CO₂ emissions. Analytical estimations demonstrate that cement reduction directly lowers process-related emissions while recycled plastic utilization diverts waste from landfills. The results confirm that environmental performance can be improved without compromising structural or thermal requirements, offering a viable solution for low-carbon construction.