Sustainable Utilization of Lightweight Aggregates in Concrete: A Review on Organic and Inorganic Waste-Based Solutions

The increasing demand for sustainable construction materials has led to the exploration of lightweight aggregates (LWA) derived from both natural and waste resources. This review examines the characteristics, benefits, and applications of lightweight aggregates in concrete, with a focus on organic and inorganic waste-based alternatives. Naturally occurring lightweight aggregates such as pumice, scoria, and diatomite, as well as manufactured aggregates from industrial by-products like fly ash, blast furnace slag, and cenospheres, are evaluated for their structural efficiency. Additionally, agro-waste materials such as coconut shells, palm shells, rice husk ash, and wood chips are investigated for their potential in producing lightweight concrete with satisfactory strength and durability. The review highlights the advantages of using these materials, including reduced dead load, improved thermal insulation, and cost-effectiveness, while addressing environmental concerns related to waste management. The incorporation of such alternative aggregates promotes sustainable construction practices by minimizing natural resource depletion and enhancing the circular economy. The study concludes that organic and inorganic waste-based lightweight aggregates provide a viable solution for eco-friendly and structurally competent concrete production.