Book excerpt: Structures throughout the United States, especially those made of reinforced concrete, have been rapidly aging and are in dire need of repair. Given the circumstances it is only natural that new, more efficient technologies, such as fiber reinforced polymer (FRP) materials, emerge to solve this worldwide aging infrastructure. FRP systems have the ability to be customized through the use of different FRP configurations, installations, and also different material properties. Through the suggested design procedures, engineers have the ability to determine the level of capacity of these existing systems and then assess and design for their future needs. Whether reinforced concrete structures are comprised of beams, columns, or slabs, FRP's can be used to improve strength and ductility while benefiting from a large service life extension. The engineer should evaluate all aspects of the project, including the structures location. The natural environment has the ability to degrade these FRP materials depending on the exposure to different elements, as well as, the duration of time exposed to these elements over the life of the system. The material should be chosen and designed with these considerations in mind to maximize the benefits of this rehabilitation technique.