In order to evaluate the behaviour of square and rectangular concrete columns wrapped by
fibre reinforced polymer (FRP) sheets, subjected to axial loading were studied. Six specimens
were tested and numerically analyzed using finite element method (FEM). The factors
affecting the performance of FRP wrapping in rectangular columns under the action of axial
loads are considered in this paper. These factors include the rectangularity ratio of the column
cross section. Techniques to improve the performance of strengthening rectangular columns
were also proposed and evaluated in the paper. Such techniques include rounding the sharp
edges of the columns, and transferring square into circular columns using mortar. A total of
six half-scale reinforced concrete columns, divided into two groups, are tested in this
research. The first group consists of three square columns, while the second group consists of
three rectangular columns. A three-dimensional finite element models are developed to
examine the structural behaviour of the RC columns before and after applying FRP sheet.
Nonlinear finite element analysis is performed using the ANSYS program. Special elements
SOLID 65, LINK 8, and SOLID 64 were used to represent concrete, discrete reinforcing steel
bars, and FRP sheet, respectively. The experimentally evaluated nonlinear material properties
for each material component are defined for the nonlinear finite element analysis. The
numerically obtained results are correlated to the experimental ones. The developed finite
element analysis models are capable of effectively simulating the behaviour of square and
rectangular columns confined by FRP sheets when the proper material properties are adopted.