Study on the oblique seismic behavior of reinforced concrete L-shaped columns strengthened with carbon fiber reinforced polymer slabs

Abstract

The oblique seismic performance of reinforced concrete L-shaped columns is an important factor that affecting the safety of structures. However, there is limited research on the oblique seismic performance of reinforced concrete L-shaped columns strengthened with carbon fiber reinforced polymer (CFRP) slabs mounted at the column bottom. In order to address the theoretical gap and meet the practical requirements, finite element analyses were conducted on L-shaped reinforced concrete columns. These analyses considered various parameters, including loading angle, strengthened method, volume stirrup ratio and axial compression ratio. The seismic performance indexes of L-shaped columns such as failure state, hysteretic curve, skeleton curve, carrying capacity, and ductility are investigated. The analyses results show that the failure mode of L-shaped column is bending failure, and the seismic performance of strengthened L-shaped column is better than that of unstrengthened L-shaped column. The CFRP slabs mounted at the column bottom could increase the peak carrying capacity and decrease the ductility coefficient of specimen. Therefore it is suggested to employ the method of strengthening column bottom by CFRP slabs in practical engineering application. Moreover, the peak carrying capacity of specimens under different loading angles is similar. With a higher loading angle, the positive peak carrying capacity of specimen increases, while the negative peak carrying capacity decreases. Finally, this study presents a novel method for determining the compression-bending carrying capacity of reinforced concrete L-shaped column, where the influence of torsion action is taken into account. This method offers valuable insights for the engineering design.