Experimental and numerical investigations of partially encased composite columns under axial load

In current international practice, composite construction is gaining importance in industrial buildings and in particular in high-rise buildings. Partially encased composite (PEC) columns are one of the recent developments in composite column. Using composite columns have several advantages such as an increased speed of erection compared to reinforced concrete (RC) columns, a more cost-effective design, smaller cross-section dimensions for similar axial resistance, and a better resistance to fire and local buckling than for steel only columns in compare with traditional RC or steel only columns. One of the proper sections for columns is a cross-sectional shape that can be used in these columns. In this paper, experimental and numerical studies are carried out on three PEC columns under pure compression load. The main difference between the specimens is in the reinforcement details of the concrete. Parameters studied in numerical work, details of reinforcement, failure mode, width to thickness ratio of steel flange and distance and transverse link diameter. The results are presented in the form of axial load-displacement curves. Also, the values of experimental work were compared with the relations between the two European and Canadian regulations, which indicated that the Canadian code was conservative. The results were developed in a numerical section after validation with a laboratory specimens and the load-bearing capacity and deformation were evaluated. The evident buckling pattern in the specimens was the kind of rupture of the welds of the links and the local buckling of the flange plate between the two links. Also, the bigger interval between the two links caused an early local buckling in the specimen.