Experimental analysis of a mechanical shear connector in concrete filled steel tube column

Abstract

ResumoThis work includes an analytical and experimental study of the structural behavior of shear connectors in composite columns, composed of concrete-filled circular hollow section. For this study was adopted a structural bolt like a shear connector in order to verify the validity of the analytical expressions in ABNT NBR 16239: 2014 [1]. Was carried out a series of push-out tests, fixing the outer diameter of the hollow section and varying the thickness, the bolt diameter, the strength of concrete and the hole dimension. Analysis of the results shows that is possible to use this type of shear connector. The Brazilian prescriptions results are conservative and may be adjusted to provide strength capacity value closest to the experiment.Keywords: concrete filled steel tube, circular hollow section, push-out test.Este trabalho compreende um estudo analítico e experimental do comportamento estrutural de conectores de cisalhamento em pilares mistos, formados por perfis tubulares laminados de seção circular de aço preenchido por concreto simples. Para este estudo foi adotado um conector do tipo parafuso estrutural, a fim de verificar a validade das expressões analíticas constantes na ABNT NBR 16239:2014 [1]. Foi realizada uma série de ensaios experimentais de cisalhamento direto, fixando o diâmetro externo do tubo e variando a espessura, o diâmetro do parafuso, a resistência do concreto e a presença ou não de folga no furo. Da análise dos resultados observa-se que é viável a utilização desse tipo de conector, que as equações existentes para o dimensionamento dos mesmos estão a favor da segurança e podem ser ajustadas para fornecer valores de capacidade resistente mais próximo do experimental.Palavras-chave: pilar misto preenchido, seção tubular circular, ensaio de cisalhamento direto.

Review of Various Shear Connectors in Composite Structures

“…Ductility, buckling, and axial capacity of the composite column due to shear connectors performance were investigated through ten experimentally tested specimens. Whereas, from load-displacement analysis of experimental push-out test, Neto and Sarmanho [103] marked the judgement that bolts application in the composite column as a shear connector exhibits ductile and flexible nature. Tian et al [104] proposed a shear connector utilizing advantages of engineering cementitious concrete together with perforated steel plate connectors and perforated steel reinforcement for composite column.…”

Experimental analysis of bolts employed as shear connectors in circular concrete-filled tube columns

“…Although ABNT NBR 16239:2013 references and presents formulations for the calculation of the strength of the bolts used as shear connectors, there is little research developed regarding the use of this simple and inexpensive device used in CFSTs. However, there are some researches that stand out, such as [13]- [19], where these authors analyzed in an experimental and/or numerical way the use of the bolt as a shear connector in CFSTs. The researches conducted by [16], [17] and [18] indicate that the analytical expressions of ABNT NBR 16239:2013 are excessively in favor of the security.…”

“…The experimental technique used in this study was developed by the authors and employed in previous studies [17], [19]. This technique is based on the recommendations of the EN 1994-1-1:2004 push-out test, but adapted to the structural element to be analyzed, the CFST.…”