Mechanical self-healing of conventional and high-performance concrete incorporating SAP, crystalline admixture, and sepiolite

Abstract

[EN] This study evaluates the efficiency of autogenous healing and self-healing agents in restoring mechanical properties through three-point bending tests. The healing agents investigated include a crystalline admixture, superabsorbent polymer, and sepiolite in ordinary concrete (OC) and a crystalline admixture in high-performance concrete (HPC). Various healing conditions were compared, including: water immersion (28 and 56 days), humidity chamber storage, and presaturation combined with humidity chamber. Mechanical recovery was analyzed using flexural strength tests loading-reloading curves. A reference series (CTL) was introduced to differentiate healing effects from natural maturation. Strength and stiffness recovery parameters confirmed distinct self-healing effects. The results show that crystalline admixtures provided limited additional benefits beyond natural autogenous healing and that superabsorbent polymers and sepiolite improved self-healing in high humidity conditions. The introduced stiffness recovery parameters could detect healing effects, setting a methodological advancement over conventional indices.