Ultimate capacity of high-strength rectangular concrete-filled steel hollow section stub columns

The ultimate capacity of high-strength rectangular concrete-filled steel hollow section (CFSHS) stub columns is experimentally investigated. In the experimental programme, 22 rectangular CFSHS specimens with cross-sectional aspect ratios of 1.0, 1.5 and 2.0 were tested to failure under axial concentric loading. All the specimens were fabricated from high-strength materials. The average yield stress of the steel hollow sections was 550 MPa (N/mm(2)) while the average compressive strengths of concrete were 70.8 and 82.1 MPa (N/mm(2)). In the study, the ultimate loads obtained from the experiment were compared with the values calculated from design codes, namely EC4, AISC and ACI. The comparison of results shows that EC4 closely predicts with a difference of 6% while AISC and ACI underestimated the critical loads by 16 and 14%, respectively. It is noted that the strength of specimens decreases with the increase of cross-sectional aspect ratios. (C) 2003 Elsevier Ltd. All rights reserved.