Degradation of infrastructure due to overloading and corrosion is a major concern. FRP materials are now increasingly being used in the construction industry. Confinement of circular concrete members using FRP is a popular application. As such, studying the performance of concrete members confined by FRP jackets is quite important for both rehabilitated and new structures. This thesis presents results of an experimental study on the performance of concrete cylinders confined with glass-FRP (GFRP) sheets, carbon-FRP (CFRP) sheets. While the subject of FRP-confinement of circular concrete columns has been extensively studied experimentally and analytically, more emphasis has typically been put on the characteristics of the FRP jackets in comparison to the concrete core properties. In this paper, the performance of the lightweight concrete core on FRP jackets is explored in order to simulate the worst case scenario in old structures that were built several decades ago, and maximize the damaging effect of concrete durability. This study simulates wrapping of circular columns with FRP sheets for retrofitting applications; concrete core with different strengths has been used to evaluate the different levels of confinement induced by GFRP and CFRP jackets of different thicknesses, specimens were tested to failure under axial compression, the study showed that wraps provide substantial increase in strength and ductility of different lightweight concretes. However, increasing the strength of concrete core shows a decreasing in the confined strength gain of tested specimens with any improvement in ductility.