OMA OF RC INDUSTRIAL BUILDING RETROFITTED WITH CFRP USING SSI

Abstract

Today, there are a great number of various structures that have been retrofitted by using different FRP
composites. For this reason, more research is needed to learn more about the properties of such structures, as well as a
comparison before and after retrofitting. In this study, one story reinforced concrete (waffle slab) building is tested using
ambient vibrations, in order to get the dynamic behaviors. Slabs of this building are then retrofitted by using CFRP
composite, and then tested with ambient vibrations. At this stage it is necessary to evaluate the dynamic behavior of the
existing and retrofitted state of the building. Various types of methods of OMA, such as EFDD, SSI, etc. are used to take
action in the ambient responses. Having a purpose to learn more about the effects of FRP composite, operational modal
analysis of both types (retrofitted and no-retrofitted buildings) is conducted to evaluate their dynamic behaviors.
Furthermore, the Stochastic Subspace Identification is used through output-only modal identification. At the end of this
study, reasonable correlation is obtained between mode shapes, frequencies and damping ratios. The goal of this
research is to show and determine the effects of CFRP composite implementation on structural responses of this
building, in terms of changing its dynamical behaviors. There is an average difference of 18.844% between the
frequencies of existing and retrofitted buildings. Finally, it is shown that, in order to evaluate the frequencies and rigidity
of retrofitted structures, OMA might be used.