Design equations for concrete columns confined with hybrid composite materials
Retrofitting of existing concrete columns by wrapping them by fiber reinforced polymer (FRP) sheets, straps, or pultruded FRP shells has been gaining great interest in the research community and in industry.
New hybrid concrete columns are developed in this study for new constructions. The basic structure of the proposed hybrid column consists of an exterior PVC-FRP shell with a concrete core. The exterior
shell is commercially available cylindrical PVC pipe externally reinforced with impregnated continuous fiber in the form of hoops at different spacing. This paper presents the results of experimental and
analytical studies of the performance of axially loaded concrete columns confined with PVC-FRP tubes. Test variables include type of confinement, volume of fiber and FRP hoop spacing. The results indicate
that the new hybrid columns exhibited high strength and ductility. A new design procedure for concrete confined with PVC-FRP is proposed. Comparisons between experimental and theoretical results showed