Investigation of the fracture cracking behavior of self-healing systems by use of optical and acoustic experimental methods

Nowadays the self-healing process efficiency in loaded structural materials is evaluated by studying the damage mechanisms. Based on fracture mechanics theories, the resistance to damage and the cracking recovery can be an indication of healing performance. Experimentally, the cracking behavior is quantified by measuring the fracture energy of the material during cracking and the fracture process zone area at which the damage is expanded. In literature, damage detection at loading stage of testing and damage recovery due to healing mechanisms at the reloading stage is monitored by application of several experimental (Non-) Destructive Methods. In this study, the Fracture Process Zone (FPZ) in different heterogeneous materials (polymer and cementitious composites) is visualized in strain and deformation (crack opening-close-reopening) profiles of the crack tip area by application of Digital Image Correlation (DIC) and the fracture energy released in different stages of cracking is quantified and located by Acoustic Emission (AE). The combination of the aforementioned optical and acoustic techniques can confirm the recovery of cracked specimens in which healing mechanisms are applied