ABSTRACT
Steel–concrete composite girder bridges are recommended by American Association of State Highway and Transportation Officials-load and resistance factor design whereas noncomposite members are not and are less frequently used in the United States. Seel sections can also be classified as compact, noncompact, and slender element sections. The ratio of overall depth to the effective span length is usually about 1:25 and the ratio of depth of steel girder only to the effective span length is about 1:30. For built-up I-sections, the longitudinal stiffeners may be provided to increase bending resistance by preventing local buckling while transverse stiffeners are usually provided to increase shear resistance by the tension field action. If the longitudinal reinforcement in the deck slab is not considered in the composite section, shear connectors are not necessary in negative flexure regions. Cross frames usually consist of angles or WT sections and act as a truss, while diaphragms use channels or I-sections as a flexural beam connector.
