Time Dependent Evolution of Cracks Healing in Cementitious Materials: Cracks Closure Dynamics

Abstract

The durability of cement-based infrastructure is frequently compromised by the initiation and propagation of microcracks, which accelerate the ingress of aggressive agents and ultimately reduce structural service life. Intrinsic self-healing has emerged as a sustainable mechanism capable of mitigating crack propagation without incorporating external healing agents. Nevertheless, the spatial evolution of healing products inside cracks and the governing transport-reaction mechanisms remain insufficiently understood. This study develops an integrated reactive transport framework coupled with laboratory experimentation to investigate the temporal and spatial characteristics of intrinsic crack healing in cementitious materials. The proposed framework simultaneously considers ion migration, mineral precipitation, hydration kinetics, and progressive changes in crack transport properties to simulate healing behavior throughout the crack depth. Experimental validation was performed using X-ray micro-computed tomography (micro-CT), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), enabling three-dimensional visualization and quantitative assessment of crack closure. The experimental observations demonstrated that healing was highly heterogeneous, with greater crack closure occurring near exposed surfaces than in deeper crack regions. Numerical simulations further illustrated that crack geometry, initial aperture, fluid transport conditions, material maturity, and ionic concentration significantly influence healing efficiency. The interaction between reactive transport processes and evolving crack morphology generated a dynamic feedback mechanism that governed long-term healing performance. The findings contribute to a more comprehensive understanding of autogenous healing mechanisms and provide valuable guidance for designing durable and resilient cementitious infrastructure capable of extending service life while reducing maintenance demands.

Keywords: Autogenous self-healing; Cementitious composites; Reactive transport modeling; Micro-computed tomography; Crack closure; Mineral precipitation; Concrete durability