高强高性能细粒混凝土断裂特性研究

纤维编织网增强混凝土（textile reinforced concrete，TRC）结构薄壁轻质，具有良好的耐久性、限裂性、定向增强性．而作为TRC基体的细粒混凝土，其基本断裂参数和力学特性不同于普通混凝土，需要重新确定．为此，采用带切口的不同尺寸的三点弯曲梁研究了其断裂特性．试验结果表明：断裂过程中细粒混凝土达到失稳破坏前也要经历一个裂缝稳定发展的过程，其失稳断裂韧度基本保持不变，但起裂韧度随试件尺寸的增大而减小；对荷载一位移曲线的尾部进行修正后，得到的断裂能几乎没有尺寸效应，可作为一个材料常数．

Research on fracture characteristics of high-performance fine grained concrete with high-strength

Textile reinforced concrete (TRC) has excellent ductility and crack resistance, directional-reinforcing capability and thin wall and light weight. For the fine grained concrete used for the matrix of TRC, its basic fracture characteristics and mechanical properties, which are different from those of ordinary concrete, need to be determined. Therefore, its fracture characteristics were investigated with the three-point bending tests using various sizes of notched beams. The experimental results show that there also exists a steady crack propagation stage before unstable fracture of fine grained concrete during its fracture process, and the unstable fracture toughness does not change, but with the increase of beam depth, the initial fracture toughness decreases. After the tail of the load-deflection curve is modified, the fracture energy obtained almost does not have size effect and therefore it may be considered as a material parameter.