Advancements in self-healing concrete: Material mechanisms, durability assessment, and implications for infrastructure lifecycle management
Xiaoye Wen, Angelita M. Pagcaliwagan, Hui Hou, Xupeng Yin
Abstract
Concrete, the most widely used construction material globally, suffers from inherent susceptibility to cracking due to factors like shrinkage, thermal stress, and loading, compromising structural integrity and durability. Cracks facilitate the ingress of detrimental substances, leading to reinforcement corrosion, reduced load capacity, and shortened service life, necessitating costly traditional maintenance. Self-healing concrete (SHC) offers a proactive solution, engineered with intrinsic or augmented capabilities to autonomously repair cracks, analogous to biological self-repair processes. This review synthesizes the current state of SHC technology. It first details the material mechanisms enabling repair, contrasting limited autogenous healing (via continued hydration and carbonation) with advanced autonomous strategies. We critically examine key autonomous methods. These include microbially induced calcite precipitation (MICP); encapsulation of healing agents in microcapsules or vascular networks; and specialized admixtures such as crystalline admixtures and superabsorbent polymers. We then evaluate how SHC performance is assessed. We cover verification of crack closure, recovery of strength and toughness, and long-term durability via transport tests and accelerated ageing. We also stress the need for standardized protocols. We outline implications for infrastructure lifecycle management. Benefits include longer service life, lower maintenance, improved resilience, and gains in sustainability. Challenges include higher upfront cost, scalability, uncertainty in long-term viability, and industry acceptance.