Effect of Shape Modification on the Performance of CFRP Confined Square Concrete Columns: A Review

Abstract

Now a days fiber-reinforced polymer (FRP) confinement is one of the most important techniques used for the strengthening and repairing of concrete structures. In the case of columns, the square/rectangular columns show less effectiveness towards FRP confinement compared with circular columns due to their flat sides and sharp corners. So the strengthening of square/rectangular columns needs more attention than circular columns. The performance of square/rectangular columns can be improved by modifying the shape of columns before FRP wrapping. The researches show that varying the corner radius of non-circular columns improves the confinement area and thereby increase the confinement efficiency of FRP. Recently, curvilinearization technique was developed in which slightly curved sides are provided to existing square/rectangular sections before application of FRP. Circularization is also another shape modification method in which the existing square columns are modifying into circular sections by using segmental concrete covers before the FRP wrapping process. This paper mainly deals with these shape modification techniques in the carbon-fiber-reinforced polymer (CFRP) confined square columns.