Axial loading behavior of CFRP strengthened concrete-filled steel tubular stub columns

This paper presents the axial compression test results of concrete-filled steel tubular (CFST) stub columns strengthened with carbon fiber reinforced polymer (CFRP) composites. Both circular and rectangular specimens were tested to investigate the retrofitting effects of CFRP composites on them. The test results showed that the CFRP jackets enhanced the load bearing capacity of the circular columns effectively, whereas the enhancement was not so significant for rectangular columns. However, ductility was enhanced to some extent for those rectangular columns. A simple model is proposed to calculate the ultimate strength of circular CFST stub columns wrapped with CFRP. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature.