Mechanical and self-healing properties of engineering cementitious capillary crystalline waterproofing materials-modified concrete

Cementitious capillary crystalline waterproofing materials (CCCW) can be used as a self-healing additive. Compared with other self-healing materials and methods, CCCW directly added to the concrete matrix is easier to apply in specific projects. In this study, long-life self-healing concrete was prepared for the Palace Museum North Campus project by adding expansion agents, polypropylene fibers, and CCCW. Its mechanical properties and durability were tested. At the same time, non-destructive testing methods were used to test the crack resistance and self-healing performance. The compressive strength was around 41 MPa (28 d) for C40 group and 47 MPa (28 d) for C45 group. The compressive strengths exhibited no loss after 300 freeze-thaw cycles. The results showed that CCCW reduces early cracking and exhibits a good repairing effect on cracks below 0.2 mm. The method provided a new technical route for evaluating the healing effect.