Numerical analysis of compressive behavior of pre-damaged concrete columns strengthened with textile-reinforced ECC

Many concrete columns exhibit a decline in structural performance due to construction inaccuracy, increased load demand and corrosive environment. It is urgent to adopt necessary strengthening methods to improve the mechanical behavior of pre-damaged columns. This paper presents a numerical investigation on the compressive behavior of pre-damaged concrete columns strengthened with a composite jacket of basalt fiber textile and engineered cementitious composites (ECC). After verification of the developed FE model, the failure mechanism of the pre-damaged concrete columns strengthened with TRE (textile-reinforced ECC) under axial compression was evaluated. Furthermore, a parameter analysis was performed to address the effects of thickness of ECC layer, spacing of fiber textile and concrete core strength on the axial behaviour of the pre-damaged columns strengthened with TRE. The results showed that the reinforced columns with different pre-damage levels showed ductile failure characteristics, which was due to a good binding force provided by the textile-ECC composite reinforcement layer. The axial stiffness, ultimate compressive load, and deformation capacity of the strengthened pre-damaged columns decreased with the increasing pre-damage level. The compressive behaviour of confined pre-damaged columns could be improved by increasing thickness of ECC, reducing the spacing of textile, and decreasing strength of the core concrete, especially for the major pre-damaged column.