UHPC Steel Composite Girder: Numerical Studies on Flexural Behaviour in Negative Moment Region

Abstract

AbstractComposite girders are extensively employed in the construction of various structures including bridges due to their potential to handle different types of loading conditions. While used in continuous spans of bridges, the lack of ability of concrete to take up tensile forces developed in the negative moment regions has been a matter of concern for a long. Ultra-high-performance concrete (UHPC) is said to have superior properties, including strength, toughness and ductility compared to Portland cement concrete. This paper presents the numerical study of the hogging moment region in a continuous steel–concrete composite girder, replacing the normal strength concrete (NSC) using UHPC under static loading. Finite element models of the girders were developed using ANSYS 18.0 software to simulate the behaviour of girders subjected to 3-point static loading. The flexural behaviour of girders with UHPC slabs was compared with those made up of normal strength concrete. The effects of parameters like slab width, depth and steel grade were also studied. Analysis showed that UHPC steel composite girders exhibited a higher flexural strength compared to normal steel–concrete composite girders. The load carrying capacity of the specimens was increased by 25–30% as the slab was modelled with UHPC instead of normal strength concrete. Optimal results were obtained when the UHPC slab was used in combination with alloy steel girders.KeywordsFinite element analysisHogging regionParametric studySteel girderUHPC