Comparison of bearing capacity and hogging of axially loaded columns in a foam concrete casing

Abstract

This work identifies the operation characteristics of axially loaded metal columns located within a foam concrete casing. The structures based on steel elements structurally combined with monolithic non-autoclaved foam concrete, used as filling for cladding, were investigated. The load-bearing capacity of axially loaded columns in free and constrained loads were compared. The columns were loaded using vertical test benches, and longitudinal deformations were recorded using a TK-50M strain gauge. Transverse movements (hogging) were measured using a dial gauge. Comparative theoretical calculations for the bearing capacity of loaded columns were carried out in accordance with the building rules and regulations SP 16.13330.2017 “Steel structures”. In experiments involving static axial loading of open-section columns, an increase in the stability of constrained columns was determined, and the ratio of longitudinal hogging of columns in a free and constrained state was shown. In addition, it was revealed that the size of the casing influences the magnitude and nature of the longitudinal bending. Therefore, it became possible to save metal by reducing the cross-section of the columns, while maintaining a bearing capacity similar to that of the free columns. The study demonstrated that as the ratio of the area of the surrounding foam concrete casing to the cross-sectional area of the loaded column increases, metal savings are correspondingly higher.