Experimental investigation on tubular columns infilled with ultra-high strength concrete

Abstract

This paper presents an experimental investigation on axially loaded ultra-high strength concrete (UHSC) filled single- and double-tubular columns. The compressive strength of UHSC is up to 200 MPa. Steel fibres were added to study the effect in enhancing the ductility and strengths. For comparison, normal strength concrete filled steel tubular columns were also tested. Test results were compared with the predictions by Eurocode 4 approach. It is shown that Eurocode 4 approach underestimates the resistance of UHSC filled steel single- and double-tubular columns by 7.7% and 13.5% respectively when the confinement effect is not considered and by 0.5% and 3.7% when the effect is considered. It concludes that Eurocode 4 approach can be safely extended to predict the plastic cross-sectional resistances of UHSC filled tubular columns. However, the steel contribution ratio should be greater than 0.30 or more than 0.5% steel fibres should be added to keep sufficient performance in ductility. © 2010 The University of Hong Kong.