CFST columns strengthened with CFRP textile grid-reinforced engineered cementitious composites under eccentric compression

Abstract

This study proposes a novel technique involving the use of carbon fibre-reinforced polymer (CFRP) textile grid-reinforced engineered cementitious composites for strengthening concrete-filled steel tube (CFST) columns. In this study, the behaviour of composite columns subjected to eccentric loading was investigated. The experimental results proved that the strengthening technique was effective, particularly as the load-bearing capacities of the strengthened columns increased by 11.6%–38.2% when compared with those of the un-strengthened columns. Moreover, the enhancing effect increased with an increase in the number of the CFRP textile layers. Compared with the specimens subjected to axial loading, the eccentric-loaded specimens exhibited a lower load-bearing capacity and stiffness. Besides, the decrease in the diameter–thickness ratio and increase in concrete strength significantly enhanced the load-bearing capacity of the strengthened columns. However, a higher concrete strength increased the brittleness. A model was proposed to predict the load-bearing capacity and N–M curves. The calculation results conform with the test results.