Use of acoustic emission analysis to evaluate the self-healing capability of concrete

It has been estimated that, in Europe, 50% of the annual construction budget is spent on refurbishment and remediation of the existing structures [1]. Therefore, self-healing of concrete structures, which are very sensitive to cracking, would be highly desirable. In this research, encapsulated healing agents were embedded in the concrete matrix in order to obtain self-healing properties. Upon crack appearance, the capsules break and the healing agent is released, resulting in crack repair. The efficiency of this crack healing technique was evaluated by using acoustic emission (AE) analysis. Breakage of the capsules was proven as events with an energy higher than the energy related to concrete cracking were noticed. Upon reloading of beams with untreated cracks, fewer emissions were detected compared to beams with healed cracks. From this study it was shown that AE is a suitable technique to evaluate self-healing of cracks in concrete