Abstract

This research investigates the critical energy release rate GIC of Chilean Pinus Radiata D. Don subjected to thermal treatment, employing the Mode I Double Cantilever Beam (DCB) test. Experimental procedures were conducted on specimens oriented in the tangential longitudinal (TL) and radial longitudinal (RL) planes under varying temperature conditions (25oC, 50oC, 100oC and 150oC). The results reveal that increasing thermal treatment significantly influences the mechanical performance of the material. The modulus of elasticity (MOE) and modulus of rupture (MOR) exhibited an increasing trend with temperature, indicating enhanced stiffness and strength. Conversely, the critical energy release rate GIC demonstrated a substantial reduction with rising temperatures, suggesting a decrease in fracture toughness. The RL plane exhibited higher values of GIC compared to the TL plane, indicating anisotropic behavior in fracture resistance. These findings provide valuable insights for the structural design of timber elements exposed to thermal environments, highlighting the necessity of considering temperature effects to ensure optimal performance and durability. © 2025 Elsevier Ltd