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Cracking of cementitious materials affects the durability of concrete structures and might lead to premature failure. As manual repairs are costly and labor-intensive, self-healing mixtures have been studied. The advantage of cementitious blends lies in the inherent ability of the material to repair damage through autogenous healing. As water is essential to be present to induce autogenous healing, the healing ability can be improved by adding water reservoirs in the form of superabsorbent polymers (SAPs). As a wide variety of SAPs with different characteristics exists, an assessment of their capacity to improve the self-healing ability is necessary to optimize the mix design. While most standardized evaluation techniques are limited in their characterization potential or due to their intrusive nature, ultrasonic measurements allow for a non-destructive material characterization. Due to their sensitivity to the obtained microstructure, the damage present and the elastic properties of the material under study, the self-healing evolution can be monitored, and the results provide information on the regained mechanical performance. In the present study, various set-ups are utilized to assess the self-healing capacity of mortars with and without SAPs. The experimental framework includes coupled ultrasonic evaluations through surface wave and transmission measurements. In addition, numerical simulations were performed to isolate the healing layer and simulate the effect of healing by increasing the stiffness of the material in the crack. A comparison between experiments and simulations allowed to assess the elastic modulus of the deposited healing products.
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