Enhancement of safety of structures with FRP and FRP-SMA systems

Strengthening and repair of structures are major issues worldwide. Strengthening is required when there is an increase in the applied load, human error in initial construction, legal requirements to comply with updated versions of existing codes, or as a result of the loss of strength due to deterioration over time. The direct costs associated with replacing a structure, and the indirect costs associated with the lack of service during the period of replacement are usually high enough to make strengthening the most desirable option. Further, many bridge and building elements are subjected to significant overloads that affect the structural safety and may require strengthening. Strengthening of structures using fibre reinforced polymers (FRPs) is enjoying a great deal of popularity as a result of the unique properties of FRPs, namely, being lightweight, fatigue resistant, and noncorrosive in addition to their ease of application. As FRPs are becoming available at lower prices, a tendency toward using them as a substitute or in conjunction with steel plating (the favourite strengthening method of the 1990s) is gaining momentum. A significant proportion of the composite’s market worldwide is used for strengthening purposes in the field of structural engineering. This large growing market has forced a great deal of research and advancements in developing the standards of practice almost in every corner of the world.