Development and properties of cementitious self-healing materials based on composite complexing agents

In addressing the concerns regarding structural performance degradation and diminished service life resulting from concrete crack formation during utilization, this study has developed a cement-based self-healing material. This material utilizes a composite complexing agent composed of tartaric acid derivatives, sodium hexametaphosphate, ethylenediaminetetraacetic acid tetrasodium salt, and vinyl acetate-ethylene redispersible latex powder. The material composition was optimized, and its self-healing performance and mechanism were systematically studied. The findings indicated that when the composite complexing agent content was set at 6% by mass of cement, there was a substantial decrease in the porosity, from 34.2% to 14.2%. In comparison with the control group, specimens with a 6% composite complexing agent exhibited an 8.3 MPa increase in compressive strength and a substantial enhancement in crack sealing, with a rate increase from 73.1% to 99.7%, following 28 days of water curing.