Experimental study of the self-healing of basalt fiber reinforced polymer composites (BFRP): Influence of thermal treatment on crack resistance

This work explores the ability of basalt fiber-reinforced polymer composites (BFRP) to recover their mechanical properties after damage, thanks to a furan-based epoxy matrix capable of reversible crosslinking. The healing process is activated through a two-step thermal treatment, first at 120°C for 25 min and then at 80°C for 48 h. Mechanical testing, particularly dynamic mechanical analysis (DMA), shows that the elastic modulus can be restored to values close to or even higher than those of the undamaged state, depending on the crack size and treatment time. The self-healing efficiency, measured as the ratio of the post-healing to pre-damage elastic modulus, exceeded 100% in some configurations (up to 106%), indicating not only a restoration but also an improvement in stiffness due to micro-defect correction. However, despite this stiffness recovery, interlaminar fracture toughness decreases significantly after healing, which suggests that the fiber/matrix bonding is only partially reestablished. X-ray tomography confirms a visible reduction in porosity and crack size after treatment. Altogether, the results show that this thermally activated self-healing system has strong potential for extending the durability and reliability of composite structures, particularly in applications where maintenance is difficult or costly.