Efficiency of an Innovative Self-Healing System in Ultra-High-Strength Concrete under a Salt Spray Test

Ultra-high strength concretes (UHSC) with self-healing system based on the combined action of two additions have been developed in order to seal developing cracks, thus improving their long-term durability. The present work evaluates the efficiency of the self-healing system in aggressive environmental conditions with chloride attack. UHSC with and without the addition of the self-healing system were fabricated and cracked at 28 days of curing considering two crack width. Once cracked, the specimens were subjected to a salt spray test during 90 days and, after that, they were characterized by means of capillarity tests and colorimetric methods (chloride penetration evaluation). Unlike in the concretes without the self-healing system, the initial water absorption rate of the cracked specimens of self-healing concretes is similar to that of the corresponding un-cracked samples and almost insensitive to the crack width, thus confirming a robust self-healing mechanism that even limits chloride penetration.