Self healing behavior for crack closing of expansive agent via granulation/film coating method

• Granulation method was used to control response time of expansive agent.
• Granulated expansive agent was coated with PVA film to control time of self healing.
• Complete crack closing was observed after immersion via microscopy investigation.
• Expansive agent via granulation/coating method can control time of autonomic healing.

Although there are many self-healing approaches, these approaches have merits and demerits. The utilization of expansive agents and mineral admixtures in various approaches may be appropriate due to their good healing efficiency, compatibility with the cement matrix, and low cost. In this study, after the granulation of the CSA (Calcium Sulpho Aluminate)-based expansive agent, it was coated with a PVA film to control the time of autonomic healing. It was verified through various tests that the granulated CSA-based expansive agent with PVA film coating can control the time of autonomic healing and can prevent water migration via crack closing.