Experimental Investigation on Behavior of Giant ConcreteFilled Steel Tubular Columns with Distributive Beam Under AxialCompression

Abstract:

A series of speciemens, including three batches, of giant concretefilled steel tubular columns (called giant CFT columns hereinafter) with detailings of distributive beam under axial load were completed. The failure mode, the loadcarrying capacity of specimens and the strain distribution on distributive beam of specimens were comprehensively compared and analyzed based on experimental results. It can be observed from the test results that the load shared by core concrete is proportional to the crosssection area of distributive beam and is considerably larger than the load transmitted by the nature bond between steel tube and core concrete. Thereout, the conclusion could be drawn that the distributive beam set in giant CFT columns could transfer vertical load effectively and reliably. Meanwhile, the load transferred by distributive beam remained constant after shear plastic hinges at both ends of distributive beam were developed, and obvious plastic deformation from shear yielding to failure at the area of distributive beam ends could be observed. Finally, it could also be concluded from the results that giant CFT columns with both distributive beams and inner diaphragms gained much higher loadbearing capacity than those only with distributive beams by comparing the two kinds of specimens. Therefore, coworking performance between core concrete and steel tube could be effectively improved by distributive beam set in giant CFT columns, so that excellent axial load bearing behavior of giant CFT columns could be ensured.