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超高韧性水泥基复合材料(Ultra High Toughness Cementitious Composites,UHTCC)是一种具有良好变形性能、裂缝控制能力和耐久性能的新型水泥基复合材料,特别适用于大坝、灌渠等水工结构的加固和修补。然而现有UHTCC材料在喷射施工过程中存在难泵送、易堵管和与结构面粘结性能差等问题,难以实现大面积快速施工,制约了该材料在实际工程中的推广和应用。本文研制出了一种可连续喷射、回弹率低的UHTCC材料,同时保证了喷射过程中纤维的均匀分散,材料硬化后仍具备拉伸应变硬化和多缝开裂特征。喷射UHTCC的压缩性能、直接拉伸性能和抗折性能试验结果显示,该材料28 d龄期抗折强度为10.30 MPa,拉伸强度为2.33 MPa,拉伸应变稳定在1.5%以上,具有延性破坏特征和良好的控裂性能,其性能可满足一般水工结构的表面加固和修补要求。
Ultra High Toughness Cementitious Composites (UHTCC) is a new type of cement-based composite material with good deformation properties, fracture control and durability. It is especially suitable for the reinforcement of hydraulic structures such as dams and irrigation channels And repair. However, existing UHTCC materials have problems of difficult pumping, easy plugging and poor bonding with the structural surface during jetting construction, which makes it difficult to realize large-area rapid construction and restricts the popularization and application of the material in actual engineering. In this paper, we developed a continuous injection, low resilience UHTCC material, while ensuring the uniform dispersion of fibers in the spray process, the material is still hardened with tensile strain hardening and multi-slit cracking characteristics. The compressive properties, direct tensile properties and flexural properties of UHTCC injection test results show that the 28-d-age flexural strength of the material is 10.30 MPa, the tensile strength is 2.33 MPa, the tensile strain is stable at 1.5%, with ductile failure Features and good crack control performance, its performance to meet the general hydraulic structure of the surface reinforcement and repair requirements.