Zhang Quan, Xiao Yihuan, Han Xiangyu, Jia Bin, Zhang Kai
School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China.
School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China.
Materials (Basel). 2025 Jun 3;18(11):2620. doi: 10.3390/ma18112620.
Shotcrete, due to its excellent performance, has become widely adopted as a lining material in tunnel construction. However, research on the fracture behavior of shotcrete, especially in terms of precise fracture toughness determination methods, remains limited. In this study, three distinct batches of shotcrete with varying porosities were fabricated, and their fracture properties were evaluated using three-point bending tests. A closed-form solution was developed to calculate the fracture toughness of shotcrete used in tunnel linings, incorporating factors such as micro-structure, specimen boundaries, and geometry. The results demonstrated that the fracture toughness obtained through this method can be treated as a material constant, independent of specimen geometry. Additionally, the study emphasized the importance of considering the pore structure in the design and fracture analysis of shotcrete materials.
喷射混凝土因其优异的性能，已在隧道施工中被广泛用作衬砌材料。然而，关于喷射混凝土断裂行为的研究，特别是在精确测定断裂韧性方法方面，仍然有限。在本研究中，制备了三批孔隙率不同的喷射混凝土，并通过三点弯曲试验评估了它们的断裂性能。开发了一种封闭形式的解决方案，用于计算隧道衬砌中使用的喷射混凝土的断裂韧性，该方案纳入了微观结构、试件边界和几何形状等因素。结果表明，通过这种方法获得的断裂韧性可被视为材料常数，与试件几何形状无关。此外，该研究强调了在喷射混凝土材料的设计和断裂分析中考虑孔隙结构的重要性。
