This project included the manufacturing and testing of a prototype Hybrid-Composite Beam (HCB) bridge for railroad and highway applications.  The hybrid-composite beam is comprised of three main sub-components: a shell, compression reinforcement and tension reinforcement.  The compression reinforcement consists of SCC concrete which is pumped into a profiled conduit within the beam shell.  The tension reinforcement consists of Hardwire® steel reinforcing fabrics which run along the bottom flanges of the beams. 

        Whereas FRP materials are generally too expensive and too flexible when arranged in a homogeneous form, the strength and stiffness of the HCB are provided by a more efficient use of materials that are well suited to purely axial tension or compression.  The classical arch shape of the compression reinforcing dramatically reduces the shear carried by the FRP webs.  Due to the low density of the FRP materials and the ability to place the compression reinforcing in-situ, what results is an economical structural member that can be used in the framing system of a bridge structure in the same manner as a steel or prestressed concrete beam, but that is much lighter and well suited to accelerated bridge construction and also provides for a potentially longer service life. 

        This project was a follow-on to a concept exploration project (HSR-23) that included the fabrication and laboratory testing of a beam prototype.  That project was sufficiently successful that this  follow-on project was undertaken to build an 8-beam railroad bridge span and test it in the high-tonnage loop at the AAR's Transportation Technology Center in Pueblo, Colorado.  The final report discusses laboratory  test results and the performance of the bridge span at the Transportation Technology Center.