Autogenous healing performance of internal curing agent-based self-healing cementitious composite

In this study, a series of cementitious composite with internal curing agent incorporating ranging from 0% to 30% were prepared to evaluate their autogenous healing performance. The Clinoptilolite Zeolite was utilized as an internal curing compound to replace parts of sand for storing the water inside the cement matrix. The mechanical properties were examined via compressive and splitting tensile tests. To quantify the self-healing behavior of this cementitious composites, the samples were pre-damaged using splitting tensile method and placed in the wet/dry cycle for several days. Two non-destructive testing methods, including resonant frequency and ultrasonic pulse velocity tests, were employed to assess the healing efficiency. The results revealed that the incorporation of zeolite could enhance the compressive strength and the self-healing performance of the proposed cementitious composites. However, if the replacement percentage of zeolite was higher than 15%, the healing efficiency decreased due to the "blocking effect", which was further investigated by the water absorption test and thermogravimetric analysis (TGA).