Creep performance of CFRP confined concrete cylinders

Multiple rehabilitation techniques were implemented in order to increase the life cycle of deficient structures. One of the most promising techniques is the addition of fiber reinforced polymer (FRP) strengthening systems, which have proven to be quite effective in the confinement of reinforced concrete columns. However, important concerns regarding the durability of FRP-rehabilitated structures remain to be investigated. One of these concerns is the long-term creep behavior of FRP strengthening systems. In this study, 15 CFRP confined and unconfined concrete cylinders were submitted to sustained loading. Three short-term creep tests and four long-term creep tests, each performed over three replicates, were carried out. The parameters of the study include the level of confinement and the level of sustained stress. According to the results, confinement can effectively increase the creep resistance of concrete. This increase depends primarily on the level of sustained loading according to the confined concrete strength. For the same percentage of loading in term of ultimate strength, specimens with the highest confinement level exhibited the greatest short term creep resistance.