Valorizing Marble Processing Waste in Fiber-Reinforced Cement-Stabilized Compressed Earth Blocks: Toward Environmental Sustainability

India’s rapid urbanization and escalating housing demand urgently require sustainable building materials. Traditional burnt clay bricks, while widely used, cause significant environmental harm, including air pollution and soil depletion. This study investigates the viability of using coir fiber-reinforced, cement-stabilized compressed earth blocks (CEBs), incorporating marble processing waste (MPW), as an ecofriendly alternative for masonry construction. An extensive experimental analysis was conducted to characterize the soil, MPW, coir fiber, and cement and to determine the optimal mix proportions for maximum strength and durability. The findings indicate that soil with approximately 32% clay/silt content and a plasticity index of 9.3% is ideal for producing CEBs, meeting the established criteria for stabilized earth blocks. The optimal addition of MPW was determined to be 30%, significantly improving the dry compressive strength to 2.47 MPa for unstabilized CEBs and to 4.54 MPa for cement-stabilized CEBs, while also reducing water absorption, enhancing durability. Coir fibers, added at an optimal content of 0.5%, increased strength parameters and flexural strength, which are crucial for seismic resistance. However, higher coir fiber (above 0.5%) percentages were found to diminish compressive strength and increase water absorption. The study underscores the potential of MPW and coir fibers in creating sustainable, cost-effective CEBs to address India’s housing challenges.