Research on Using Waste Glass, Fly Ash, and Coconut Fibers to Produce Eco-Friendly Concrete for Housing Construction in the Southwestern Provinces of Vietnam

Abstract

In the context of the Mekong River Delta accelerating the development of modern, sustainable, and cost-efficient industrial zones, there is a crucial need for construction materials that are reasonably priced, environmentally friendly, and utilize local recycled resources. In the Mekong River Delta region, coir fiber is a very common agricultural waste product, similar to rice straw in the Northern region. Utilizing coir fiber as a reinforcing material in concrete not only helps to enhance crack resistance and improve certain mechanical properties of the material but also contributes to reducing product costs due to the cheap and readily available raw material source. This study focuses on evaluating the feasibility of producing concrete using various recycled materials: waste glass aggregates completely replacing crushed stone, Duyen Hai 1 thermal power plant fly ash replacing 25% of Portland cement content, and natural dispersed coir fibers to increase the concrete's crack resistance. Experiments were conducted on two strength grades, M300 and M400, with three glass replacement ratios: 0%, 50%, and 100%. The results show that the concrete mixture exhibited suitable workability (slump ranging from 17,5÷22,0 cm), compressive strength at 28 days varying from 34,5 MPa to 50,5 MPa, elastic modulus from 28,9÷35 GPa, and flexural tensile strength reaching up to 8,2 MPa due to the presence of dispersed coir fibers. Notably, low water absorption (less than 7,5%) and excellent impermeability demonstrated the effectiveness of the material system in improving the microstructure and compactness of the concrete. This concrete product is suitable for use in factory floors, machine foundations, and internal roads within industrial zones, meeting stringent mechanical and environmental requirements. Applying this solution helps reduce material costs and shorten construction time, thereby enhancing project management efficiency and promoting sustainable development in industrial zones of the Mekong River Delta.