Mechanical and dual-axis flexural behaviour of hybrid plastic waste and fly ash unsaturated polyester polymer mortar

The incorporation of cement in mortar compositions exacerbates environmental degradation via CO2 emissions. A key initiative to curtail cement usage involves substituting hydraulic cement binders with polymeric alternatives, enhancing sustainability in material testing. This research first aimed to determine the optimal composition in terms of compressive strength, density, tensile strength, and flexural strength. In this investigation, the optimal formulation emerged in RUN-16, comprising unsaturated polyester at 37%, plastic waste at 20%, fly ash at 38%, cobalt at 1.5%, and MEKP at 3.5%. This composition delivers compressive strength of 84.03 MPa, tensile strength of 10.96 MPa, flexural strength of 11.30 MPa, and specific gravity of 1427 kg/m³, as validated through rigorous mechanical testing protocols. • Optimal RUN-16 formulation achieves 84.03 MPa compressive strength with 20% plastic waste • Dual-axis flexural testing confirms isotropic structural performance • Fly ash and unsaturated polyester significantly enhance compressive rigidity • 100% cement substitution with polymer matrix eliminates cement-related CO₂ emissions • RUN-16 optimizes workability (8.41 cc/s) and multidirectional structural integrity