Strength and Ductility of HSC and SCC Slender Columns Subjected to Short-Term Eccentric Load

Although several methods to predict the ultimate strength of slender columns under eccentric loads are available, the reliability of these approaches has been extensively investigated only for columns made of conventional concrete. This paper seeks to expand available experimental data for slender columns of high strength concrete (HSC) and self-consolidating concrete (SCC). Tests were conducted on 60 eccentrically-loaded slender columns constructed of HSC, SCC, and traditional vibrated concrete. All columns have cross sections of 100 x 100 mm (3.94 x 3.94 in.) and lengths of 2000 mm (78.8 in.). The main variables considered in the tests were the concrete strength, the longitudinal steel reinforcement ratio, and the load eccentricity. Attention is focused on the overall performance of columns: type of failure, cracking pattern, peak strength, and ductility. Findings from the tests carried out with small eccentricity indicate that the ultimate normalized strengths of SCC slender columns are lower than the strengths obtained for the traditional vibrated concrete columns. The tests carried out with medium and high eccentricities showed comparable strengths. The tests on SCC columns made of normal-strength concrete showed very soft and ductile failures. In these columns, cracking patterns are located along the whole length of the specimens with a high number of cracks. More concentrated damage was observed in the medium-strength concrete and HSC columns. The ductility of slender columns was higher for the SCC columns made of normal-strength concrete. For medium-strength concrete and HSC, no notable differences were observed between SCC and vibrated columns.