Properties of Plastic-Based Composite Panels Manufactured from Municipal Waste Under Accelerated Weathering as Potential Paving Slabs

This research examined the mechanical, physical, thermal, and durability properties of plastic-based composites made from MSW, namely ultra-high-temperature (UHT) cartons, plastic bags, aluminum foil, and foil bags under both unweathered and accelerated weathering conditions to evaluate their potential as paving slab materials. Composite samples with varying mixing ratios were fabricated and tested based on an experimental design. Statistical analyses using one-way ANOVA confirmed the significant effects of composition on material performance (<i>p</i> < 0.05). The results demonstrated that the mixing ratio markedly influenced mechanical properties. The composite containing 50 wt% UHT carton and 50 wt% foil bags (U50F50) achieved the highest modulus of rupture (121.20 MPa) and modulus of elasticity (2.98 GPa), as well as compressive strength (28.56 MPa), compressive modulus (2.12 GPa), screw withdrawal resistance (54.25 MPa), and hardness (66.25). Under accelerated weathering, all of the composites showed moderate reductions in strength (10 to 30%) due to plastic degradation and surface cracking. In contrast, the composites containing high paperboard fractions (U80P15A5) exhibited greater WA (3.55%) and TS (3.04%), attributed to the hydrophilic nature of cellulose. The inclusion of foil bags effectively reduced WA and TS by limiting moisture penetration. Density measurements demonstrated a gradual increase (0.99 to 1.05 g/cm³) with higher foil content, while accelerated weathering induced an average 10% density reduction. Abrasion resistance improved in foil-rich composites, with U50F50 showing the lowest weight loss (8.56 to 14.02%), confirming its superior structural integrity under mechanical wear. Thermal analysis indicated low conductivity values (0.136 to 0.189 W/m·K), demonstrating favorable insulation performance compared to conventional paving materials. However, higher foil bag fractions enhanced heat conduction, balancing mechanical strength with thermal functionality. Overall, MSW-derived composites containing 30 to 50 wt% foil bags exhibited optimal mechanical durability, abrasion resistance, and thermal stability, making them promising candidates for sustainable paving slab production with low environmental impact and enhanced service life.