Valencia bridge fire tests: Experimental study of a composite bridge under fire

Abstract

The consequences of bridge fires and the lack of guidelines on the evaluation of the fire resistance of bridges have triggered a lot of recent research. Most of these studies are based on numerical models and thus need validation by experimental studies.This paper aims to bridge this gap by describing a battery of open air fire tests carried out under an experimental bridge at the Universitat Politècnica de València in Valencia, Spain. The bridge, with a 6m span and a composite deck with two steel I-girders supporting an RC slab, was submitted to four different fire scenarios similar to those of real bridge fires, although smaller in magnitude. Results show that: (a) maximum gas temperatures are reached in the region between the I-girders, (b) as gas and steel temperatures vary significantly along the longitudinal axis of the bridge, it is unrealistic to assume a longitudinally uniform gas or girder temperature (c) temperatures in the bottom flange and the web of the I-girders are very similar and significantly higher than top web temperatures, and (d) the magnitude of the fire load and its position are key factors in the bridge response. This study is of major importance as it enables the validation of the numerical models used in bridge fire engineering and is a crucial step towards the development of a performance-based approach for the design of bridges against fires. The information given will also be useful to those interested in carrying out open air experimental bridge fire tests.