Experimental Research of the Strength of Compressed Concrete Filled Steel Tube Elements

The purpose of this article is to study the effect of the compressing force eccentricity on the strength of compressed concrete filled steel tube elements of circular section, produced from high-strength concrete. The behavior of short laboratory samples with 159 mm cross-section diameter was investigated under axial and eccentrical compression in low and high eccentricity areas. Self-stressing concrete was used to produce half of the examined samples. The conducted research results indicate high utilization efficiency of the steel shell for high-strength concrete core of concrete filled steel tube elements behaving not only under centric compression but also under eccentrical compression with low eccentricities. The application of self-stressing concrete for such samples allows increasing the confining effect by approximately another 5%. To a greater extent, the presence of self-stressing concrete has increased the elastic strength limit of structures.