R/C Existing Structures with Smooth Reinforcing Bars: Experimental Behaviour of Beam-Column Joints Subject to Cyclic Lateral Loads
Franco Braga2, Rosario Gigliotti 2, Michelangelo Laterza 1, *
Identifiers and Pagination:Year: 2009
First Page: 52
Last Page: 67
Publisher Id: TOBCTJ-3-52
Article History:Received Date: 17/02/2008
Revision Received Date: 15/01/2009
Acceptance Date: 16/03/2009
Electronic publication date: 15/5/2009
Collection year: 2009
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The paper illustrates the results of experimental tests performed on sub-assemblages of R/C (Reinforced Concrete) existing structures, designed only for gravity loads In order to estimate failure mechanisms and ductility properties, four internal and external R/C beam-column joints were built and tested. The specimens were built by using concrete with low strength and smooth reinforcing bars, without hoops into the panel zone. The tests were performed by increasing cyclic horizontal displacements up to the collapse. The experimental results show that seismic response of these kind of structures is mainly influenced by bond slips of longitudinal bars, and that the shear collapse regards external joints rather the internal ones. Failure mechanisms observed (column plastic hingings for internal joints, shear failure for external joints) point out the vulnerability of these structures due to the soft storey mechanism. The study is significant for better understanding of the inelastic seismic behavior of the R/C existing buildings with smooth bars, and for evaluating the effectiveness of the model classical assumptions.