Evaluation of self-healing by a combination of ultrasonic measurements and 3D numerical simulations

Abstract

Self-healing concrete became an attractive resolution to costly and labour-intensive manual repairs. Up to now, the regain in mechanical performance is generally assessed using destructive tests, which are not suited for in-situ measurements, nor for monitoring purposes. Hence, ultrasound was adopted, combining a non-intrusive character together with a direct correlation to the elastic properties. Ultrasound has shown its potential to evaluate repair and self-healing processes in literature. The wave velocity provides a direct link to the global E-modulus. However, the healing layer cannot be separated from the intact material that is included in the investigated area. Therefore, ultrasonic measurements are combined with 3D numerical wave simulations. Through a comparison between experiments and simulations, an estimation of the elastic properties of the healing layer was performed. Furthermore, a method to evaluate the stiffness and the filling ratio of healed layers within the crack is proposed, based on wave velocity and amplitude.

Keywords

• Cement
• Self-healing
• Ultrasound
• Wave simulations
• Superabsorbent polymer (SAP)
• Hydrogel