Effect of Binary-Use Mineral Admixtures for the Advanced Autogenous Self-healing Behavior of Fiber-Reinforced Cementitious Composites

This paper comprises the enhanced self-healing properties of fiber-reinforced cementitious composites by taking advantage of synergistic effect of using different mineral admixtures. To do this, single and binary use of metakaolin (MK) and zeolite (Z) were utilized in cement-based mixtures, and early age self-healing behavior of specimens was assessed based on sorptivity tests. The autogenous self-healing performance of each mixture was also evaluated via crack width assessments by using a video microscope. Results were compared with the sound and preloaded specimens having different crack width levels. In addition, mechanical properties of four different mixtures were evaluated by conducting experiments on 7 and 28 days. The multiple crack width closures and sorptivity coefficients of preloaded specimens indicated that an effective combination of MK and Z can trigger a higher level of self-healing in comparison with reference mixture. However, single-use of Z in mixtures was also promising for achieving autogenous self-healing attributes compared to mixtures containing only MK and to reference mixtures. Having said that, this behavior should also be addressed for different pre-cracking and prolonged curing age of each mixture.