Green lightweight concrete utilizing sustainable processed recycled plastic aggregates: Technical, economic and environmental assessment

Abstract

In recent years, it has become imperative to conduct studies on the environmental effect of the construction industry on sustainability and develop strategies to mitigate sustainability risks. These mitigation strategies aim to protect natural resources and reduce waste accumulation. The life cycle analysis of buildings has been one of these studies due to the adverse environmental effects of the materials utilized in construction, particularly concrete. Specifically, how material use affects global warming and consumer desires for energy-efficient and environmentally friendly buildings. This study presents a comprehensive life cycle assessment of operational and embedded energy components that affect overall energy consumptions for concrete construction. Five concrete mixtures with varying percentages of sustainable recycled plastic aggregate were compared to a control mixtures made with normal weight and natural lightweight aggregates using a case study of a two-story residential building in Saudi Arabia. A life cycle assessment was initially used to estimate the embodied impact of producing the concrete. Then operational energy use was simulated using IES-VE. The weathering profile, transportation distance, and processing energy were all considered and calculated using site-based data for the environmental impact assessment components. The results demonstrate significant reduction of annual operational energy, carbon emissions and overall energy consumption of up to 15%, 13% and 21%, respectively. Therefore, the resulting green concrete system is more environmentally friendly due to the superior thermal performance over existing natural lightweight aggregates concrete. This evidence enables the ideas to be implemented, particularly in dry climate countries such as Saudi Arabia, where the average electricity use is very huge. Additionally, the study results suggest the possibility of permanently integrating plastic wastes into sustainable aggregate and its subsequent green concrete to reduce these wastes' adverse effects.