Axial behavior of reinforced concrete columns confined with FRP jackets

This paper presents the results of an experimental investigation of the axi al behavior of small-scale circular and square plain concrete specimens and large-scale circular and square reinforced concrete columns confined with fiber reinforced polymer (FRP) composite jackets, subject to monotonic, con centric axial loads. Improvements in the axial load-carrying and deformatio n capacities of FRP jacketed concrete members over unjacketed members are r eported. Factors influencing the axial stress-strain behavior of FRP confin ed concrete, such as transverse dilation and effectively confined regions a nd their relationship to jacket properties, are identified and discussed. F actors necessary to calibrate in situ jacket behavior and reported or measu red FRP material properties are proposed and their interrelationships discu ssed.