Effect of autogenous crack self-healing on mechanical strength recovery of cement mortar under various environmental exposure

Abstract

While research on self-healing of cement-based materials has recently gained considerable attention and made sizable progress, there is still ongoing debate and controversy regarding the effect of crack closing induced by autogenous self-healing on mechanical strength recovery. Despite that several techniques have been used to capture and quantify the self-healing of surface cracks, the resulting effect on mechanical strength has not, to date, been explored and quantified in a rigorous and systematic manner. Therefore, in this study, a broad array of multi-scale techniques including non-destructive shear wave velocity, high-resolution X-ray computed tomography (µCT), and 3D image analysis was deployed to examine the effects of autogenous crack self-healing on the mechanical strength recovery in various mortar specimens. The influence of microstructural changes induced by additives such as swelling compounds, silica-based additions, and carbonating minerals on strength recovery under diverse environmental exposures was further explored. The results capture the relationship between the crack closing mechanism imparted by self-healing and mechanical strength recovery, therefore elucidating the discrepancies in mechanical strength recovery results reported in the open literature.

Autogenous self‐healing of concrete: Experimental design and test methodsA review

“…However, measurements were found to be independent from calcite precipitation and mainly influenced by the formation of CSH phases 35,36,39,114 . Results of Suleiman et al 123 agree with these findings and show that the regain of strength is most pronounced for samples incorporating fly ash due to the ongoing pozzolanic reaction. A similar behavior of latent hydraulic cements is expected by the latter authors.…”

Recent Advances of Self-Healing Materials for Civil Engineering: Models and Simulations

“…The efficacy of self-healing in cementitious materials is significantly affected by the composition of cement matrix, encompassing factors such as the type and proportion of cement, the moisture level, aggregate characteristics, and the duration of the healing period [31][32][33][34][35]. Huang et al [32] reported that slag cement pastes exhibit a higher potential for autogenous healing compared to Portland cement pastes.…”

Avaliação do desempenho mecânico e absorção capilar de concretos com incorporação de aditivos cristalizante submetidos a danos nas primeiras idades

“…Conforme explicado por ROIG FLORES et al [12] e REDDY e RAVITHEJA [44], um aditivo cristalino apresenta características hidrofílicas, promovendo o aumento da densidade do C-S-H e a redução da permeabilidade do concreto. Além disso, os produtos de hidratação gerados pela mistura cristalina promovem a densificação da microestrutura e reduzem a sucção capilar [50]. Logo, os arranjos internos dos poros dos concretos são influenciados pelas fissuras, afetando a absorção capilar de água [51].…”