Experimental investigation of post-tensioned concrete bridge beams exposed to hydrocarbon fire

Abstract

This paper presents the fire tests of six scaled post-tensioned bonded concrete bridge beams, which simulate the action of hydrocarbon fire. The test variables considered include beam section type, fire exposure time and loading level. The phenomena observed during testing, including water evaporation, smoke, flame, noise, etc. were recorded. The temperatures and displacements at critical locations were measured. The measurements of displacement and loading after fire exposure were utilized to evaluate the post-fire load-carrying capacity. Results showed that the box girders under lower loading sustained for around 3 hours before collapse, while those under higher loading sustained for around 2.5 hours. Results also showed that about 12% of load-carrying capacity at ambient temperature was lost after exposure to simulated hydrocarbon fire for around 1.5 hours. Post-fire evaluation showed that the specimens experienced severe spalling during fire exposure.