Experimental study of the seismic behavior of obliquely loaded concrete columns reinforced with high-strength steel bars

In order to further study the seismic behavior and working performance improvement path of reinforced concrete columns under oblique earthquake action, seven concrete columns with HTRB630 steel bars were designed. The loading direction axial compression ratio and column end restrained pattern were chosen as the main design parameters. The low cyclic reversed load test has been carried out on understanding the seismic performance of the specimen. Based on the test study, the characteristics including the failure mode, hysteresis loops behavior, carrying capacity, ductility, stiffness degradation and energy dissipation ability were demonstrated. The results show that under the axial compression ratio of 0.6, the compressive carrying capacity and deformation capacity in 45 degree direction was about 82% and 78% of that in the principal axis direction, respectively. The load carrying capacity and deformation capacity in 45 degree direction under the axial compression ratio of 1.0 can be significantly improved by using steel plate mesh and carbon fiber cloth restrained manner. It is necessary to further study the effective measures to improve the restrained degree on damage development of inner concrete for the local area grid restrained manner. A method for calculating the normal-section flexural capacity of a column based on the equivalence principle was also developed, and its results were found to be consistent with those of the tests.