Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi'an 710123, China.
Institute of Transportation, Inner Mongolia University, Hohhot 010070, China.
Molecules. 2020 Mar 10;25(5):1251. doi: 10.3390/molecules25051251.
Frost damage of concrete has significant effects on the safety and durability of concrete structures in cold regions, and the concrete structures after repair and reinforcement are still threatened by cyclic freezing and thawing. In this study, the new-to-old concrete interface was reinforced by steel bar. The shear strength of the new-to-old concrete interface was tested after the new-to-old combination was subjected to cyclic freeze-thaw. The effects of the diameter of the steel bar, the compressive strength of new concrete, the number of freeze-thaw cycles and the freezing temperatures on the shear properties of new-to-old concrete interface were studied. The results showed that, in a certain range, the shear strength of the interface was proportional to the diameter of the steel bar and the strength of the new concrete. Meanwhile, the shear strength of the reinforced interface decreased with the decreasing of the freezing temperature and the increasing of the number of freeze-thaw cycles.
混凝土的冻融损伤对寒冷地区混凝土结构的安全性和耐久性有重大影响，而且经过修复和加固的混凝土结构仍然受到循环冻融的威胁。在这项研究中，通过钢筋对新老混凝土界面进行了加固。在新老混凝土组合经历了循环冻融之后，对新老混凝土界面的抗剪强度进行了测试。研究了钢筋直径、新混凝土抗压强度、冻融循环次数和冻结温度对新老混凝土界面抗剪性能的影响。结果表明，在一定范围内，界面的抗剪强度与钢筋直径和新混凝土强度成正比。同时，加固界面的抗剪强度随着冻结温度的降低和冻融循环次数的增加而降低。
