Numerical simulation of flexural breaking load resistance tests in mortars with recycled polyethylene terephthalate

This study investigates the flexural behavior of mortars modified with recycled polyethylene terephthalate through numerical simulations developed in SolidWorks Simulation using a linear dynamic approach. Prismatic specimens measuring 40×40×160 mm³ with recycled polyethylene terephthalate contents of
10 and 20% were evaluated under three temperature levels (20, 150, and 350 °C) and two curing conditions: ambient and water curing. A linear dynamic finite element model was developed in SolidWorks Simulation to reproduce the bending response and analyze the temporal evolution of Von Mises stresses, principal stresses, and stress distribution patterns. The numerical model incorporated experimentally determined mechanical properties and breaking loads as input parameters. The results indicate that increasing recycled polyethylene terephthalate content reduces the stiffness and load-bearing capacity of the mortar, particularly at elevated temperatures, due to the thermal softening of the polymer and the weakening of the interfacial transition zone. Water curing enhances mechanical performance by promoting matrix hydration and improving the capacity for stress redistribution, thereby mitigating the adverse effects of thermal exposure. The numerical simulations showed strong agreement with experimental observations and successfully captured the evolution of stress localization and failure mechanisms under different thermal and curing conditions. These findings highlight the combined influence of recycled polyethylene terephthalate content, curing regime, and temperature on the structural performance of modified mortars and confirm the suitability of linear dynamic finite element analysis for investigating bending behavior in polymer-modified cementitious materials.