Comparison of test methodologies to evaluate steel-concrete bond strength of thin reinforcing bar

The evolution of concrete is enabling the production of slender reinforced concrete components with the application of thin rebars. Although there are many studies related to the steel-concrete bond, a specific standard for bond tests of thin rebars is still missing. This paper presents some questions about methodologies for bond tests and the geometry of pull-out test specimens. This paper also presents bond coefficient (ηb) values for thin rebars. An experimental programme was performed for this purpose. The results showed that cylindrical specimens in pull-out tests presented bond-strength values closer to bond-strength values from beam tests. A test methodology adopting cylindrical specimens is suggested.