In recent decades, Fiber Reinforced Polymer (FRP) material has increased its importance in the construction industry. FRP is a non-metallic reinforcement material which has been used in the strengthening structures especially concrete structures. The applications of the FRP material in the construction industry brought about an interesting alternative for structural retrofitting. FRP materials are lightweight, high strength-to-weight ratio, stiffness-to-weight ratio has high chemical resistance, ease to install, minimal labor cost and non-corrosive. These characteristics make FRP superior to traditional structural retrofit materials such as steel plates.
Structural retrofit is a common phenomenon in the construction industry. Retrofitting is needed when one or a combination of the following situations are encountered: a) structural deterioration caused by the environmental changes, b) additional load carrying capacity needed due to occupancy change and c) when construction or design mistakes are made which result to inadequate reinforcement for a structure. FRP retrofit is done by mounting FRP to the tension side of a member to be retrofitted using epoxy which is used as the bonding agent. The nature and characteristics of the bond layer have some influence on the performance of a structure with anomalies in the bond layer, such as uneven thickness of epoxy or voids in structure itself which lead to debonding. Debonding is caused by high stress distribution on uneven location. These anomalies are usually a result of poor workmanship during the process of grinding the surface before the installation of FRP material.
The objectives of this study were to assess the effects of anomalies on a structure that was retrofitted by FRP material and produce a remedy to the structure affected by these anomalies. The experiment conducted showed that anomalies affect structures that are retrofitted by FRP. One way of resolve this problem is by impregnating FRP material to a structure which is good in tension to avoid debonding. This method was found to be useful since it increases the load capacity for about 20%.
