ABSTRACT
Composite materials made of fibers in a polymeric resin, known as fiber-reinforced-polymers (FRP) have emerged as an alternative to traditional materials. There are a number of available externally bonded FRP systems, such as Wet Layup FRP system, Prepreg FRP system, and Procured FRP system (ACI 440 2002). The main advantages of the externally bonded FRP system include lightweight, noncorrosive and high-tensile strength of the FRP. Substantial experimental and theoretical research has been conducted over the last decade into the effectiveness of using FRP sheets/strips to strengthen or retrofit RC members and the behavior of the strengthened structural elements (Grace et. al. 1999, Grace 2002, ACI 440 2002, Tavakkolizdeh & Saadatmanesh 2003, and El-Hacha & Rizkalla 2004). Most of these investigation used non-prestressed method by gluing or bolting the FRPs to the members’ surfaces. However, the method of gluing or bolting FRPs to the members’ surface has a common problem of debonding and hence could not fully utilize the full tensile strength of the FRP (Lopez & Naaman 2003).
