Compressive behavior of RC columns strengthened with FRP and prefabricated UHPC blocks

Abstract

The combined strengthening method of cross-sectional shape-modification and lateral FRP confinement has been proven to be capable of significantly improving the compressive behavior of RC column and the FRP confining efficiency. However, the traditional shape-modification method using a cast-in-place concrete jacket has a complicated construction process and a long curing period. Additionally, the application of normal concrete substantially increases the cross-sectional area and weight of the column, resulting in poor seismic performance of the strengthened column. In this study, a novel strengthening method using FRP and modular prefabricated ultra-high performance concrete (UHPC) blocks is proposed for strengthening RC columns. An experimental study was conducted to investigate the axial/eccentric compressive behavior of RC columns strengthened with this novel method. The test results demonstrated the high efficiency of the proposed method in enhancing the load-carrying and deformation capacities of the RC columns under axial or eccentric compressive loads. The significant roles of the strengthening components in the novel method in improving the compressive behavior of columns were also verified.