关键词: 水泥基渗透结晶型防水材料(CCCW);高延性水泥基复合材料(ECC);力学性能;自愈合性能;孔隙结构;物相组成;微观形貌;

Abstract: To design an Engineered Cementitious Composites(ECC)with excellent mechanical and self-healing properties, ECC doped with ultrahigh molecular weight polyethylene short-cut fiber(PE-ECC)was used as a benchmark group and was mixed with different types and amounts of Cementitious Capillary Crystalline Waterproofing materials(CCCW).Compressive tests, flexural tests, and tensile tests were used to test their mechanical properties, and the prefabricated crack method was used to analyze their self-healing properties.XRD,MIP,and SEM were used to examine the phase composition, pore structure and micro-morphology of the materials.The results showed that the mechanical properties of PE-ECC tended to increase first and then decrease with the increase of CCCW doping.The mechanical properties were best when the doping amount was 1%.The mechanical properties of the PE-ECC were more obviously improved by XYPEX-type CCCW,with the compressive strength of 53.8 MPa, flexural strength of 11.8 MPa, ultimate tensile stress of 5.56 MPa and ultimate tensile strain of 7.53 MPa, which were 37.95%,53.25%,14.17%,and 21.65% higher than those in the reference group respectively.The change of resonance frequency and crack width showed that CCCW had a significant enhancement effect on the self-healing performance of PE-ECC,which could effectively repair cracks less than 0.5 mm, and the self-healing ability of both types of CCCW was similar.MIP test showed that CCCW could effectively improve the pore structure of PE-ECC.XRD and SEM tests showed that the types of self-healing products of PE-ECC remained unchanged after the doping of CCCW,but the types of Ca2+ complex agents increased, and the ability to provide Ca2+ became stronger.The distribution of self-healing products at the crack was denser, and the degree of healing is higher compared to others.

Key words: cementitious capillary crystalline waterproofing material; engineered cementitious composites; mechanical property; self-healing property; pore structure; phase composition; microscopic morphology;