FULL-SCALE TEST OF CONCRETE-STEEL HYBRID BRIDGE GIRDERS

A full-scale laboratory test was conducted on a unique hybrid bridge g irder with a reinforced concrete web and steel flanges. Half-width pre cast concrete deck panels were compositely attached to the top steel f lange of a 17.1 m long hybrid girder to construct a ''half-bridge'' th at was tested to study the service load behaviour and the behaviour un der increasing load until failure. It was observed that the concrete w eb of the hybrid girder cracked because of the combination of dead wei ght and restrained shrinkage. Under the service loads, the concrete we b had numerous closely spaced cracks that were reasonably well control led - the maximum crack width was 0.20 mm. Although there was signific ant diagonal cracking in the web of the girder, the ultimate behaviour was dominated by flexure. This paper presents the methods used to con struct and test the half-bridge, and a summary of the important result s. A companion paper presents a detailed analysis and discussion of th e test results.