ON DEFINITION OF THE DESIGN RESISTANCE TO COMPRESSION OF LONGITUDINAL REINFORCEMENT OF TUBE CONFINED CONCRETE COLUMNS

Abstract

Columns made of steel pipes, filled with concrete, are one of the few successful examples when
concrete and steel are mutually and substantially help to resist force effects, which results in increased
bearing capacity of the element as a whole. Tube confined concrete constructions have a number of significant
advantages compared to reinforced concrete or metal ones. The main of them are high bearing capacity,
rigidity and reliability, low labor intensity and high speed of building a frame. Eventually, all this
leads to reduced consumption of material and financial resources for manufacturing. The promising areas
for further improvement of steel tube confined concrete columns are preliminary lateral compression of
the concrete core or its rational reinforcement. The paper presents the main results of experimental research
studies on the bearing capacity of prestressed and traditional tube confined concrete columns
with reinforcing of the concrete core. Based on these data it’s concluded that the rational use of prestressing
and high-tensile reinforcement in steel tube confined concrete columns has led to an increase
in their bearing capacity up to 20 %. The authors have proposed formulas, which take into account the
effect of a concrete and reinforcement grade, as well as the reinforcement ratio on the value of design
resistance to compression of high-tensile reinforcement.
Keywords: experimental research studies, steel tube confined concrete columns, bearing capacity,
high-tensile reinforcement, design resistance to compression.