Strengthening the Concrete Columns Wrapped With Fiber Reinforced Polymers

In recent years, it is on the process of development that the polymer materials are used in strengthening and retrofitting the concrete elements. Fiber-reinforced polymers (FRP) have emerged as an alternative solution to traditional materials for strengthening and retrofitting structures, especially in existing structures which need to build-up or when changing the use of the structure. In the attempt to increase strength and ductility of reinforced concrete (RC) load bearing elements through confining systems the FRP membranes have become a familiar solution. Extensive studies (experimental, finite element modeling and analytical modeling) were carried out on the analysis of confining effect in case of concentrically loaded RC columns. This paper investigates the prospect of strengthening deficient square columns and cycle column with carbon fiber-reinforced polymer (CFRP) jackets. In both cases, output results will be compared with the etalon specimen (without strengthening). Currently, the study of RC columns confined with composite materials will be focused in centric compression, because the eccentric compression is relatively new and limited. FRP confinement systems are less effective under eccentric loading compared to concentric. Experimental program on testing the performance of centric loaded RC columns externally strengthened with CFRP membranes was carried out and results are presented in this paper.