Performance and mechanisms of stimulated self-healing in cement-based composites exposed to saline environments

Performance and mechanisms of stimulated autogenous self-healing in cement-based composites with addition of crystalline admixtures (CAs) exposed to water, seawater and NaCl solutions were investigated. Crack closure, chloride penetration, water absorption and healing products were characterized for cracked mortars exposed to wet/dry cycles. Moreover, leaching and hydration of cement affected by CAs were studied to reveal mechanisms of stimulating self-healing. The slight difference in self-healing products formed in the three saline solutions between mortars with and without CAs indicated that the capacity of stimulated self-healing strongly depends on exposure environments. Correlation between crack closure and durability recovery for cracked specimens sug-gests a need for performance-recovery-based method for assessing the self-healing ability. Comparison of two commercial CAs having different alkalis and effects on cement hydration revealed that mechanisms of stimulated self-healing vary significantly with the type of CAs.

Automated summary

This study investigates the performance and mechanisms of stimulated autogenous self-healing in cement-based composites with the addition of crystalline admixtures (CAs) exposed to different saline solutions. The results show that the stimulated self-healing capacity strongly depends on the exposure environment, and the correlation between crack closure and durability recovery suggests the need for a performance-recovery-based assessment method. Furthermore, the type of CAs significantly affects the mechanisms of stimulated self-healing.