Synergistic Utilization of Industrial, Agricultural, and Plastic Wastes in Brick Production Through Statistical Modeling

ABSTRACT Rapid growth in plastic waste and construction–demolition debris had strained disposal systems while the clay‐brick industry remained energy intensive, creating demand for masonry units that consumed wastes without kiln firing. Fly ash and sugarcane bagasse ash had provided reactive or microfiller functions, and a polyolefin‐rich plastic stream had supplied a thermoplastic binder, motivating a composite route. The objective was to engineer and optimize a plastic–mineral brick using plastic waste, fly ash, construction–demolition fines, and a fixed 5% bagasse ash, ensuring that the compressive strength and water absorption met code‐relevant thresholds. A special‐cubic response surface mixture design was implemented; all wastes were characterized, melt‐mixed at 110°C–120°C, molded to standard dimensions, and tested for compressive strength and 24‐h cold‐water absorption per IS 3495, while a composite desirability function enabled simultaneous optimization. The best formulation—23.64% plastic waste, 35% fly ash, and 41.36% CDW with 5% SBA—achieved 14.06 N/mm 2 compressive strength and 2.9% absorption, and strong interaction effects, particularly between plastic and CDW, were identified; the optimized solution reached a desirability of 1.000. These properties placed the units within the IS 1077 Class‐15 strength band with absorption far below the specification limit, indicating suitability for partitions, infill masonry, façade panels, and pedestrian‐grade pavers. The findings signaled a practical pathway to divert heterogeneous wastes into durable building products through low‐temperature processing and statistically guided proportioning. Future work was proposed to extend field‐scale durability monitoring and to integrate cradle‐to‐gate environmental accounting with pilot manufacturing.