Field Load Test Behavior of Composite

In Brazil, the composite log-concrete bridges are being considered as a viable alternative for municipal and rural use, mainly because of their low construction cost, low maintenance needs and their high strength and stiffness. The system consists in a thin concrete slab over round timber beams. Materials are thus used to their best abilities where timber is in tension and concrete in compression. The connection between the two components is realized through glued steel bars. This paper presents the field performance of a composite log-concrete bridge constructed in December 2004 at São Paulo University Campus. This two-lane bridge is 12 m long, 10 m wide, with a skew of 15 degrees. The load tests consisted of positioning fully loaded, three-axle trucks on the bridge and measuring the resulting deflections at a series of locations along a transverse cross section at midspan. In addition, an analytical assessment using computer modeling was completed to predict the response of the bridge. The field tests indicate that the composite log-concrete bridge is performing adequately with no structural deficiencies