Self-healing of Engineering Cementitious Composite with Crystalline Admixture Under Different Exposure Conditions

Abstract

Self-healing mechanisms in concrete can promote healing of cracks with the material produced through the concrete itself. Engineered Cementitious Composites (ECC) is a special category of HighPerformance Fiber Reinforced Cementitious Composites (HPFRCC) that has been extensively investigated for self-healing purposes. Hydration of unhydrated binders in the matrix and precipitation of calcite were recognized as the two main mechanisms to cause self-healing in ECC. In addition, the high portions of fly ash and Polyvinyl Alcohol (PVA) fibers in the mixture improves the mechanism; however, small crack widths were reported to be healed in this material. The current experimental program aims at determining the extent of self-healing in large cracks by providing favorable conditions. Crystalline Admixture (CA) is also used as a self-healing promoter to increase the crack filling capacity. Three different exposure conditions of air dry, tap water, and sea water were tested using a water permeability (WP) test. The results indicate high sealing capacities in a short period for specimens made with CA and submerged in sea water.