Study of a Precast-Prestressed Model Bridge Slab

摘要

A half-scale concrete composite model bridge slab was studied to evaluate the structural performance of a 36-foot long, two-lane, highway bridge span. The proposed composite member is composed of a prestressed concrete channel, an interior void form, and a top slab of cast-in-place concrete. A theoretical analysis of the load distribution behavior of an orthotropic plate based on the Guyon-Massonnet distribution theory is presented. Application of the theory to this particular bridge system together with a sample calculation is presented in an appendix. An 18-foot long, 12'6 wide model bridge span consisting of five prestressed channels and a cast-in-place top slab was constructed for the purpose of experimental verification of the analytical analysis. Two series of tests were conducted in this study. In the first series of tests a single concentrated load was applied to a grid of 30 load points. The load distribution behavior was studied in terms of the distribution pattern of the measured deflections. In the second series of tests a simulated S16 trailer load was applied to the two-lane model bridge slab. The wheel load distribution, the ultimate behavior of the system, and the failure mode were investigated. Complete composite action was observed through the test and the failure resulted from compression crushing of the top slab in the vicinity of the load line. (Author)