Seismic Performance of Full-Scale Joints Composed by Concrete-Filled Steel Tube Column and Reinforced Concrete Beam with Steel Plate-Stud Connections

Abstract

A concrete-filled steel tube (CFST) column has the advantages of high bearing capacity, high stiffness, and good ductility, while reinforced concrete (RC) structure systems are familiar to engineers. The combinational usage of CFSTand RC components is playing an important role in contemporary projects. However, existing CFSTcolumn-RC beam joints are either too complex or haveinsufficientstiffnessattheinterface,sotheirpracticalengineeringapplicationhasbeenlimited.Inthisstudy,theresultsofa practical engineering project were used to develop two kinds of CFSTcolumn-RC beam joints that are connected by vertical or U-shaped steel plates and studs. The seismic performance of full-scale column-beam joints with a shear span ratio of 4 was examinedwhentheyweresubjectedtoalow-cyclicreversedloadingtest.Theresultsshowedaplumpload-displacementcurvefor theCFSTcolumn-RCbeamjointconnectedbysteelplatesandstuds,andtheconnectionperformancesatisfiedthebuildingcode. ThebeamshowedabendingfailuremodesimilartothatoftraditionalRCjoints.Thefailureareawasmainlyconcentratedoutside thesteelplate,andtheplastichinge movedoutwardfromtheendsofthebeam.Whenthecalculatedcrosssectionwassetatthe end sof the beam,the bending capa city of joints with the vertical or U-shaped steel plate sand studs increased compared to theRC joint. However, when the calculated cross section wasset to the failure area,the capacity was similar to that of theRC joint. The proposed joints showed increases in the energy dissipation, average energy dissipation coefficient, and ductility coefficient compared to the RC joint.