RECENT ADVANCES IN SELF-HEALING CONCRETE TECHNOLOGY: MECHANISMS, MATERIALS, PERFORMANCE EVALUATION, AND FUTURE RESEARCH DIRECTIONS FOR INFRASTRUCTURE

Abstract

Self-healing concrete represents a paradigm shift in construction materials science, addressing the fundamental brittleness and cracking tendency of traditional concrete through mechanisms that enable autonomous or autogenous repair of structural damage. [1] Recent research has demonstrated that self-healing concrete can repair cracks up to 1.8 mm width through bacterial precipitation and calcite production that seals cracks, which could extend the serviceability of concrete. [2] This review synthesizes current knowledge on self-healing mechanisms, materials, performance evaluation methods, and future directions. Five primary strategies for implementing self-healing capability are discussed: (1) autogenous self-healing through intrinsic carbonation and crystallization, (2) biomineralization through bacteria-produced carbonates, (3) polymer-cement composites with autonomous healing, and (4) fiber-based crack inhibition. [1] While autogenous techniques have limited efficacy for cracks exceeding 0.3mm, autonomous techniques have successfully repaired cracks exceeding 2mm in width. [3] Bacterial systems are capable of healing cracks up to 0.5-0.8 millimeters with high recovery of structural strength, with emerging evidence suggesting potential environmental impact benefits through longer structural life and reduced maintenance rates. [4] This comprehensive review identifies critical research gaps and proposes standardized testing protocols to facilitate industrial adoption of self-healing technologies in sustainable infrastructure development.