Composite bridges are structures that combine materials such as steel, concrete, timber or masonry in any combination. In this context, however, composite construction is usually taken to mean either steel and in-situ concrete construction or precast concrete and in-situ concrete. Steel-concrete composite bridges are usually more expensive. However, they are often competitive due to other reasons / advantages, particularly for medium span girder bridges (l | 40. This article provides a description of the. FRP materials offer bridge designers the advantages of high stiffness-to-weight and high strength-to-weight ratios when compared to conventional construction materials such as steel and reinforced concrete. FRP can be preformed into complete structural units, thus reducing construction time. The design and construction techniques already popular for the I-beam form of composite bridges can be used to produce. From the Greek Bronze Age (around the 13th century BC) to the rise of stone arch bridges, and later the widespread adoption of iron, steel, reinforced concrete, and advanced composites, bridge engineering has continuously adapted to new construction capabilities and modern demands. In 2026, bridges. The California Department of Transportation (Caltrans) has been engaged in cooperative research with various researchers, universities, and material suppliers to stay abreast of the latest developments in engineering materials.