Experimental Study of Tubular Flange Girders

The behavior of I-shaped steel girders with flanges made from concrete-filled tubes is investigated experimentally, focusing on concrete-filled tubular flange girders (CFTFGs) in positive bending regions where the concrete-filled tube is the compression flange. The investigation included CFTFGs that are either composite or noncomposite with a concrete deck. For the composite CFTFGs, girders with rectangular tubes and either a flat web or a corrugated web are studied, and for the noncomposite CFTFGs, girders with round tubes and flat webs are studied. The objectives are: (1) to provide experimental data demonstrating the load carrying capability of CFTFGs and the advantages of CFTFGs over conventional I-girders; and (2) to verify the adequacy of analytical models by comparing experimental and analytical results. The experimental results demonstrate the improved lateral torsional buckling capacity of CFTFGs, and their capability to carry factored design loads under construction conditions and in the final constructed condition. The comparison between experimental and analytical results shows the adequacy of simple analytical models for CFTFGs.