Effectiveness of Autonomous Self-healing in High-Performance Concrete Exposed to Freeze-Thaw Cycles

Concrete is a globally prominent construction material, cherished for its capacity to withstand substantial compressive stress, affordability, and adaptability in shaping. Nonetheless, concrete is not immune to weaknesses, including susceptibility to tension-induced cracking, shrinkage, fatigue loading, and environmental exposure. Such cracks, once formed, can jeopardize structural integrity, durability, and overall longevity. To counter these challenges, the concept of autonomous self-healing in concrete has emerged. This process enables concrete to regain its performance post-initial damage by incorporating artificial substances like bacteria or capsules containing healing agents into the concrete mix, facilitating crack repair. This notion draws inspiration from self-healing mechanisms observed in biological lifeforms, resembling plants and animals. This paper explores concrete’s self-healing process via an autonomous system exposed to harsh environmental conditions, elucidating the underlying mechanism through experimentation. The study evaluates the efficacy of healing capsules, their incorporation ratio, and resistance to freeze-thaw cycles. Significantly, introducing 0.5% sodium silicate into the concrete matrix yields notable improvements in freeze-thaw cycle resistance, leading to satisfactory compressive strength performance. These findings underscore the effective utilization of self-healing properties in this concrete mixture, promising enhanced durability and longevity.