Seismic Retrofit of Reinforced Concrete Structures Using Fibre Reinforced Polymer

Aging and deteriorating infrastructure, and more strict seismic design standards, call for the need of seismic retrofitting. Amongst various seismic retrofit strategies, use of fibre reinforced polymer (FRP) is both effective and advantageous over many other techniques, chiefly due to its high strength-to-weight ratio and good fatigue strength. Further, the speed of installation of FRP being high, it results in reduced downtime, that is extremely beneficial in case of seismic retrofitting of crucial infrastructure. The retrofit techniques with FRP are designed to add ductility, confinement, moment and shear capacity to existing structural members. Thus, local strengthening of members is achieved and alterations to overall structural dynamic properties are minimal. Amongst the commonly used fibres, glass fibres are suitable in low-cost seismic retrofit applications in comparison to carbon. However, caution needs to be exercised over the performance of FRP under elevated temperatures, as fire is a common hazard associate with earthquakes. This chapter discusses the various aspects of FRP retrofitting of reinforced concrete structural elements, as well as of masonry infill walls, for enhanced seismic performance.