Experimental study of prestressed steel-concrete composite beams with profiled steel decking

Abstract

Steel-concrete composite beams with concrete slab cast on profiled steel decking are widely used in bridges and building construction. Prestressed tendons can be added to the beams to increase their structural performance in new structures or in retrofitting. However, no experimental data was found in the literature that investigated prestressing associated with profiled steel decking in composite beams. This paper presents an experimental study that investigates the behavior of simply supported prestressed steel-concrete composite beams with profiled steel decking under positive bending moment. Tests were carried out both on a beam with straight tendon profile placed at the beam's full length and on a conventional non-prestressed composite beam, and deflections and strains were measured. The beams were mounted in a four-point bending test configuration and then loaded. The tests terminated due to excessive deformations of the models and safety concerns, and no particular failure mode was observed. Then, a numerical model to simulate the behavior of the composite beams was developed and validated with the test data. The numerical models indicated that the failure mechanism in both beams consisted in yielding of the tensioned steel beam. It was found that adding prestressing can increase the ultimate moment by up to 19% and significantly reduce deflections under service loads.