Natalli, Juliana FadiniXavier, Ellen MartinsCosta, Laís Cristina BarbosaRodrigues, Bárbara HéllenSarmanho, Arlene Maria CunhaPeixoto, Ricardo André Fiorotti2022-09-262022-09-262021NATALLI, J. F. et al. New methodology to analyze the steel–concrete bond in CFST filled with lightweight and conventional concrete. Materials and Structures, v. 54, 2021. Disponível em: <https://link.springer.com/article/10.1617/s11527-020-01579-5>. Acesso em: 29 abr. 2022.1871-6873http://www.repositorio.ufop.br/jspui/handle/123456789/15491The construction sector is constantly seek- ing for new building systems that are cheaper, faster and with a reduced generation of residues. In this way, the use of concrete-filled steel tubes (CFST) increased due to its fast and clean execution, and its high mechanical strength, durability and ductility. The performance of this system depends on the steel– concrete interaction that occurs in the form of a natural bond. The present work evaluates the natural bond mechanisms manifested in thin-walled steel tubes filled with three types of concrete: conventional, lightweight and lightweight with expansive admix- ture. Push-out tests were realized in the CFSTs and the results were compared with bond strength values prescribed by international standards. Finally, the residual concrete adhered to the CFST interface was evaluated by a new methodology using visual resources. Results indicated that the lower modulus of elasticity of the lightweight concretes contribute to the enhancement of the confinement effect and microlocking. And the expansive admixture improved the adhesion performance of the filling core. Addi- tionally, the new methodology presents a good correlation with the other tests and it is easy to apply.en-USrestritoExpansive admixtureConcrete filled steel tubeArtigo publicado em periodicohttps://link.springer.com/article/10.1617/s11527-020-01579-5https://doi.org/10.1617/s11527-020-01579-5