Scientific paper ID 1553 : 2018/1

Subject of the publication is design in ultimate limit states of reinforced concrete elements with circular cross-section and evenly distributed longitudinal reinforcement along the periphery subjected to a bending moment and a compression force.

Circular cross-section is common in reinforced concrete elements such as building columns, bridge supports and cast-in-place piles. Most often with such elements the longitudinal reinforcement is evenly distributed along the periphery of the cross-section. When the elements are subjected predominantly to bending, part of the longitudinal reinforcement falls within the compression zone and works under compression together with the concrete, another part works on a tensile. Besides the deformations in the reinforcement, which is located near the neutral axis are elastic and the stress level is low, in reinforcement, which is away from the neutral axis can develop plastic deformation and the stress reach the yield strength. Taking all these factors into account makes it difficult to design reinforced concrete elements with circular cross-section.

The purposes of this publication are:

 to determine the change in longitudinal force and bending moment in the reinforcement in areas where the deformations of the reinforcement are nonlinear,

 to create an algorithm and to make an example table under this algorithm for determining the d reinforcement for elements with circular cross-section subjected to a bending moment and a compression force.

An example is given in the publication, which shows the order in determining the reinforcement.