Experimental investigation on the self-healing effect of coral concrete cracks based on microorganisms

Le résumé fourni par la source

The service life of concrete is closely related to crack generation and repair, which has become a major concern in the industry. Traditional passive repair methods are effective but require significant human and financial resources. Recent research on active crack repair focuses on microbial-induced calcium carbonate precipitation (MICP) for self-healing. However, most studies still rely on manually filling cracks with self-healing agents after damage occurs, limiting true self-repair capability. This study proposes incorporating a microbial self-healing agent directly into concrete to enable autonomous crack healing. Based on the MICP principle, the aerobic alkaliphilic bacterium Bacillus subtilis is used as the core of the self-healing agent. The bacteria are immobilized on coral sand and mixed into coral concrete. Prefabricated microcracks are created using a liquid press machine, and the healing performance is evaluated over different curing periods. Crack healing is assessed using surface observation and ultrasonic velocity methods, while mineralization products are characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Finally, the effects of the self-healing agent on compressive strength and carbonation resistance of the concrete are analyzed.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.