Seismic performance assessment of different fibers reinforced concrete columns using incremental dynamic analysis

Abstract

Different fiber-reinforced concrete (FRC) has been widely used in the recent decades, which can improve the mechanical behavior and dynamic performance of reinforced concrete (RC) columns remarkably. This paper aims to compare the seismic behavior of columns constructed with different FRC material, namely steel fibers reinforced concrete (SFRC), polypropylene fibers reinforced concrete (PFRC) and steel-polypropylene hybrid fiber reinforced concrete (HySPFRC). 3-D nonlinear finite element models have been built to represent the seismic behavior of different FRC columns, which are calibrated with the available experimental results of quasi-static tests. The seismic capacity of bridge columns with different FRC material are assessed based on four flexural damage states through the nonlinear static pushover analysis, such as a) yielding of longitudinal steels; b) core concrete crushing; c) buckling and d) fracture of longitudinal of steels. Incremental dynamic analyses (IDA) are conducted using the selected suite of 20 near-fault as-recorded ground motions to evaluate the inelastic seismic responses of different bridge columns. IDA curves are generated based on the intensity measure, namely peak ground acceleration (PGA) in this paper and seismic demands (i.e. maximum drift, residual drift, displacement ductility and curvature ductility) through nonlinear dynamic time-history analysis. It can be concluded from the IDA results that the SFRC, PFRC and HySPFRC are all effective to enhance the seismic performance, thus reducing the anticipated damage of the bridge columns. Moreover, SFRC and HySPFRC are more effective to improve the seismic capacity of bridge columns for the slight and moderate damage states, while PFRC and HySPFRC are more effective at the extensive and complete damage states.