Experimental Research On HBR500 High-Strength Reinforced Concrete Bridge Columns

Bridge as an important part of the modern transportation network, exhibiting good seismic performance in the earthquake is very important. Seismic performance of the bridge structure depends mainly on the seismic performance of bridge columns. To improve the seismic performance of bridge columns under earthquake, taking into account the promotion of HRB500 high strength steel bars in bridge construction in order to achieve the effect of energy saving, proposed using HRB500 high strength longitudinal reinforcement and HRB500 stirrups, analysis its seismic performance in order to provide the theoretical basis of the application of HRB500 high strength steel in bridge columns.This experiment design four rectangular piers specimens bridge columns, stirrup strength and longitudinal reinforcement strength is considered as two variable parameters. Based on the low cyclic loading experiments on the four RC bridge columns, the seismic performance in terms of the damage characteristic, bearing capacity, ductility, hysteretic characteristic, rigidity degradation and energy dissipation of HBR500 RC bridge columns are compared and analyzed. The results show that the failure modes of HRB500 RC bridge columns is bending failure, it is similar to the failure modes of ordinary bridge columns. Using HRB500 high strength longitudinal reinforcement can significantly increase the carrying capacity of the specimen, postpone the rigidity degradation, slow down the speed of rigidity degradation. The displacement ductility of HRB500 stirrups is better. The hysteresis loop of HRB500 RC bridge columns is fuller than it of ordinary bridge columns, the area of hysteresis loop is larger, has better energy dissipation capacity and deformation capacity, it also has greater rigidity. Therefore, the use of HRB500 steel bars can improve the seismic performance of bridge column components, it is conducive to seismic.Through the analysis of the hysteresis curves and skeleton curves obtained by experiment, establish a degradation trilinear restoring force model suitable for HRB500 RC bridge columns. Through statistical regression analysis of the data obtained by experiment, propose the method of establishment of the skeleton curve model, rigidity variation and hysteretic rules and path. Also put forward the specific calculation method for each of the feature points on the skeleton curve model, and obtain the theoretical skeleton curve of each specimen in this experiment by this method, the theoretical skeleton curves were compared with the experimental skeleton curves, the comparative result is seen closer. It is shown that the skeleton curve model established before can better reflect the hysteretic behavior of RC bridge column with HRB500 high strength steel bars.