Fifty-Year Development: Construction of Steel Hybrid Bridges

Hybrid construction of bridges has developed over the past 50 yr, beginning with composite concrete deck bridges during the twenties, progressing through prestressed and autostressed hybrid girders, ad now including orthotropic girder bridges. The progress of the composite girder is traced primarily through the evolution of the shear connector. The hybrid girder originated with prestressed girders and developed into the autostressed hybrid girder. The modern hybrid girder is little different from a normal girder; however, its presence represents a true advancement in furthering the economy of steel bridge construction. The orthotropic girder bridge was brought about by the industry's need to develop bridges with maximum economy of material. This type of structure is perhaps the most recent totally new idea in bridge construction. The roadway quality is of great importance to this bridge and the wear surface has advanced considerably.