Calculation Models for Combined Bending and Axial Compression in Concrete-Filled Circular Steel Tube Columns

Resumo

Steel-concrete composite columns are load-bearing elements that combine steel and concrete, with or without reinforcement, working together to resist axial compression and flexural-compressive forces. This solution stands out when compared to steel columns, as the integration with concrete enhances protection against corrosion and fire. Similarly, when compared to reinforced concrete columns, it enables the use of smaller cross-sections while maintaining the same strength. In this context, ABNT NBR 8800:2024, which sets the design standards for composite columns, proposes three calculation models for verifying the resistance to combined flexural and axial compression. The aim of this study is to evaluate the calculation methods outlined in the latest revision of the Brazilian standard, as well as to develop a computational tool using Mathematica Software to determine the flexural-compressive strength of concrete-filled circular sections. Additionally, numerical applications based on examples from the literature are used to compare the results obtained for each calculation method. Thus, the research not only contributes to a deeper understanding of the new regulatory criteria but also aims to assess and compare the calculation models for concrete-filled circular steel tubular columns.