Experiment on Flexural Fatigue Performance of Precast Bridge Deck Joints with Loop Connections

With the background of bridge industrialized construction, as a convenient construction form of a joint, a joint with loop connections has been applied in the connection of the precast bridge deck. As a relatively new type of connection structure, the fatigue performance and degradation law of a loop connection joint are still not clear. In this paper, different flexural fatigue specimens are designed based on the application situation of the loop connection joint. After 0 to 2 million fatigue-loading cycles, the fatigue-loading process is suspended and the static flexural performance of the specimen is tested. The load-deflection curves of specimens under static loading remain roughly linear, and the slope changes little. After 200 × 104 fatigue-loading cycles, the failure mode of each specimen is still presented as typical pure flexural failure. In addition, the strain of steel and concrete changes little, as well, and the stiffness degradation of each specimen is not obvious. It is indicated from this experiment that the fatigue-loading cycles has little effect on the mechanical properties of the concrete and loop bars, and the joint with loop connections has good fatigue performance.