Issued as a Documentation Report on an Investigation of Field-Made Joints in Prestressed Reinforced Concrete Highway Girder Bridges, Project IHR-303, Phase 2

Abstract

A prototype bridge girder was designed, built, and tested. The 250 ft long two-span girder was made of 3 precast segments about 88, 74, and 88 ft in length. The segments were supported on 3 final and 2 temporary supports. The joints were of cast-in-place concrete, as was the composite deck. After the site-cast concrete was cured, the structure was post-tensioned to establish continuity and the temporary supports were removed. The two longer segments were pretensioned to resist the girder and deck dead loads, while the shorter segment was reinforced with deformed bars for the same loads. The structure was subjected to a series of loadings, during which deflections, reactions, and concrete strains were measured. The loads approximated AASHTO HS-20 vehicles. The first 4 tests ,were to service loads, with total applied loads of 73.6 kips. The structure remained elastic and crack free during these tests. Two tests were to the design ultimate load, 198.7 kips. A load of 328.2 kips was applied in the final test without causing failure. The final loading was applied to produce maximum shear in one splice, and a shear failure, complicated by large flexural deformations, appeared to be developing when the test ended. The final test produced a maximum deflection of 10.8 in., and a residual of about 1.0 in. The joint details used in the prototype structure were adequate, and the presence of the, joint had no influence on the behavior of the structure until extremely large overloads were reached.State of Illinois Department of TransportationU.S. Department of Transportation. Federal Highway AdministrationProject IHR-30