Visualization of the healing process on reinforced concrete beams by application of Digital Image Correlation (DIC)

Fabrication of concrete with Self-Healing capabilities has become recently a hot research topic. In general, material science is focused on the development of smart engineering concrete and cementitious composites with extended service life. Indeed, materials that remain durable and keep their mechanical performance, damage mechanisms occurring should heal by themselves. In the case of this study formation of damage and recovery of the mechanical properties is investigated by application of an encapsulated healing agent. On experimental level, it is imperative to implement an optical, non- contact and on-line technique to visualize and compare the crack propagation at the loading and reloading (when the initial cracks are filled by the healing agent) stage. For that reason, optical measurements by application of Digital Image Correlation (DIC) are performed during the tests. Processing images captured by a 4-digital cameras system during all the loading stages of four-point bending tests give a full- field view of the crack displacement and strain profiles. A step further, the visualization of the cracking phenomena by DIC offers a useful tool to apply fracture theories of concrete on healing systems.