Development of eco-friendly lightweight foamed concrete using waste marble powder and waste glass powder

The increasing embodied carbon dioxide emissions and the growing consumption of natural resources in the construction sector are driving the search for more sustainable solutions to mitigate these impacts. Using recycled materials in construction is an effective strategy for enhancing environmental sustainability and improving resource efficiency. With the ever-increasing volumes of marble and glass waste generated worldwide, it has become essential to explore practical approaches for incorporating these materials into construction applications. This research aims to develop a concrete mixture that reduces cement and sand usage by examining the partial replacement of cement with waste marble powder (WMP) as a cementitious material and the partial replacement of sand with waste glass powder (WGP) as a filler. Several studies have demonstrated positive effects of using marble or glass waste individually; therefore, this study investigates their combined influence on concrete performance. This research focuses on evaluating the effects of these substitutions on the mechanical properties (compressive and tensile strength) and physical properties (density and workability) of lightweight foamed concrete (LWFC) to produce a lightweight and environmentally friendly mixture. Sixteen mixes were prepared using varying proportions of WMP and WGP (0%, 5%, 10%, and 15%). The results showed a reduction in density (1679–1798 kg/m 3 ) and compressive strength up to 47.2% for WMP and 39.4% for WGP as the replacement levels increased, along with a noticeable improvement in workability. Based on the balance between strength and weight, the optimal substitution levels were identified as 5–10% WMP as a cement replacement, 15% WGP as a sand replacement, and a combined mix containing 5% WMP and 5% WGP. Furthermore, future research should investigate the durability and microstructural characteristics of LWFC containing WMP and WGP, as well as assess the environmental and economic benefits associated with their large-scale application in the construction sector.