Fiber reinforced polymers for structural retrofitting: A review

Many structures located in seismically active zones are not capable of withstanding seismic action according to current codes and provisions. Furthermore, recent earthquakes in urban areas have clearly demonstrated an urgency to upgrade and strengthen these seismic deficient structures. Significant amount of research work has been carried out in recent years to develop various strengthening and rehabilitation techniques to improve the seismic performance of structures. Several strengthening methods like addition of new structural elements; external post tensioning, steel plate bonding etc. has been applied in the past with varying degree of success. Among these methods, seismic retrofit with FRP materials has gained notable acceptance from the civil engineering community in recent years. Retrofitting with FRP materials is a technically sound and cost effective repair technology and is now extensively being used as a seismic retrofitting method all over the world. This paper presents a representative overview of the current state of using FRP materials as a retrofitting technique for the structures not designed to resist seismic action. It summarizes the scopes and uses of FRP materials in seismic strengthening of RC structures and masonry retrofitting as well as the seismic retrofitting schemes for steel structures. The advantages along with the design guidelines and the limitations of FRP applications for seismic retrofit are also included in the paper.