FLEXURAL CAPACITY OF COMPOSITE GIRDERS ACCOUNTING FOR BRIDGE HIGH PERFORMANCE STEEL

Abstract

Elasto-plastic finite element analyses are used in a parametric study to investigate the positive flexural capacity of composite steel girders. The flexural capacity of steel-concrete composite girders using high-performance bridge steel (SBHS) is investigated with regard to web slenderness limits. Furthermore, an investigation is conducted regarding the impact of the initial (early) bending moment resulting from the unshored (unsupported) construction approach on the limits regarding web slenderness for the section classification. The findings from the composite girder's FE simulation model show that the flexural capacity of the composite bridge girders resisting a positive bending moment distribution, predicted by currently designed codes, is particularly conservative. The potential compact-noncompact limit is greater than that of AASHTO and Eurocode by around 50 and 70%, respectively. Many sections show acceptable flexural capacity as noncompact while being categorized as slender by current criteria.