Static and dynamic experimental analysis of precast concrete beam-to-column connection stiffness

Author(s)

Sandra Freire de Almeida

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2010-10-18

Examining board members

Joao Bento de Hanai; Pedro Afonso de Oliveira Almeida; Roberto Chust Carvalho; Jose Samuel Giongo; Petrus Gorgônio Bulhões da Nóbrega

• Advisor: Joao Bento de Hanai

Abstract

Usually precast concrete connections are considered as perfect joints (pinned or rigid), however the real behavior can be intermediate what is called semi-rigid. The use of dynamic tests is an advantage to obtain stiffness values without damaging the structure and can be used to assess the real boundary conditions or verify the need for structural strengthening. This research aims to develop a dynamic experimental procedure to determine the beam-to-column connection stiffness of precast concrete structures directly from accelerometer measured data. The preliminary tests were carried on specimens of real size or reduced scale, as well as concrete or steel connection specimens with different boundary conditions. The experimental tests were conducted in a reduced scale concrete frame composed of precast columns and beam. The frame was tested through dynamic and static methods in order to obtain the beam-to-column stiffness value directly. The beam was connected to the columns by pinned connections, formed by support cushions and dowels. In addition, the connections were strengthened by embedding CFRP strips in the lateral concrete cover, according to NSM technique (Near-Surface Mounted). Experimental static and dynamic tests were done at different loading steps. The results obtained with concrete and steel models show good agreement between static and dynamic tests. (AU)