Impact resistance capacity and degradation law of epoxy-coated steel strand under the impact load

Abstract As the main load-bearing component of the bridge structure, the cable is damaged by the impact from time to time, so it is very important to clarify its impact resistance capacity. Based on the method of the drop-weight test, this article mainly studies the degradation law of the mechanical properties of epoxy-coated steel strand (ECSS) under the impact load. Through the impact test of ECSS under different working conditions, the influence law of prestress, impact energy, initial defects and other factors on the impact resistance of the steel strand was revealed. Then, the difference of the impact resistance of ECSS and ordinary steel strand (OSS) was verified under the same impact conditions. Finally, the failure mechanism and the residual-bearing capacity of ECSS were analyzed through the secondary impact test. The results show that the initial prestress is helpful to improve its impact resistance when it is less than 0.11 f u {f}_{{\rm{u}}} , and exceeding this value will accelerate its failure process. The effect of impact height on the strain at the impact point of ECSS is significantly greater than that near the anchor end. ECSS has better energy absorption characteristics than OSS. The impact resistance of ECSS with initial defects is very sensitive to the impact energy. The influence on outer strand in the secondary impact is significantly higher than the central strand, and its residual tensile capacity still has 0.85 f u {f}_{{\rm{u}}} .