Safety-shaped concrete bridge railings and traffic barriers using GFRP reinforcement

The demand for the development of a more efficient and durable transportation infrastructure is among the top priorities of highway authorities worldwide. In the United States, the economic impact of steel corrosion for concrete highway bridges is estimated to exceed 15 percent of total annual costs. Degradation affecting steel reinforced concrete (RC) bridge superstructures exposed to harsh environmental conditions is not limited to decks, but includes railings and barriers and can significantly compromise their crashworthiness. Glass fiber reinforced polymer (GFRP) is highly suitable for reinforcing concrete structures subjected to corrosive environments and a number of projects have demonstrated its viability as an alternative reinforcement for bridge decks. Until recently, most traffic barriers using GFRP bars were vertical-faced systems. However, the impact time duration of vertical-faced barriers is shorter causing higher peak forces to be transferred to vehicle occupants. Nowadays, GFRP manufacturers can produce standard bar bends which can be used for the reinforcement of safety-shaped concrete railings and barriers. The implementation of GFRP bar bends requires some changes in the current design philosophy for railings and barriers. Whereas the overall goal of the research program is to make the technology of concrete bridge reinforcement with composites available to bridge owners and professionals, this paper provides the principles for the design of safety-shaped GFRP-reinforced concrete railings/barriers.