FUTHER INVESTIGATION ON COMPOSITE COLUMNS WITH HIGH STRENGTH STEEL AND ULTRA-HIGH STRENGTH CONCRETE

摘要

This paper extends the previous experimental work to investigate the behaviour of concentrically and eccentrically loaded steel tubes infilled with ultrahigh strength concrete (UHSC) with compressive strength up to 180 MPa. Both hot-finished S355 hollow tubes and welded steel box sections with S700 plates were used to prepare the long column test specimens. The cross section configurations consist of single-tube and double-tube sections infilled with concrete. Test results obtained include loaddeflection plots, maximum loads and failure modes. The maximum loads from tests were compared with Eurocode 4 predictions by extending its limitations on the material design strengths to include high strength steel S700 and UHSC C180. The paper recommends that Euvocode 4 simplified method can be used to predict the maximum resistance of the CFST columns with high strength materials, and they are feasible for use in high-rise buildings with reduced column size.