Determination of Crack Healing Efficiency of Concrete Containing Crystalline Admixture in Experimental Procedures Using Image Analysis

Crystalline admixtures are often used as waterproofing agents added in the concrete mixture and have the capability of promoting self-healing of concrete. Sika WT-200 P is one of the examples of crystalline admixture typically used at 0.8–2% by cement mass. In this paper, concrete test specimens containing crystalline admixture were cracked using two methods and exposed to different environmental conditions then analysed for crack healing ability using image analysis done through in-house code. Self-healing is visible within the first 7 days of hardening in the test specimens immersed fully in water. After 100 days, images are taken using a Canon camera. The images are converted into grayscale then binary images are produced which show that self-healing has occurred, and the average crack width has been reduced by as much as 90% in some cases. The compressive strength of these specimens is as high as 90 MPa beyond 100 days of self-healing tests.