APPROVED BY:
Assoc. Prof. Cem Yalçın . . . . . . . . . . . . . . . . . . .
(Thesis Supervisor)
Assist. Prof. Kutay Orakçal . . . . . . . . . . . . . . . . . . .
Assoc. Prof. Ercan Yüksel . . . . . . . . . . . . . . . . . . .
DATE OF APPROVAL: 15.01.2013
ACKNOWLEDGEMENTS
I would like to express my gratitude to everyone who contributed the development of this research. I would like to express my sincere gratitude to my advisor Assoc. Prof. Dr. Cem Yalçın for his valuable help in instructing, guiding and supporting me throughout the duration of this thesis.
Also, I would like to thank the members of my Master’s thesis examination committee; Assist. Prof. Kutay Orakçal, and Assoc. Prof. Ercan Yüksel, for their in-depth comments and advice.
I would like to thank Assist. Prof. Ahmet Anil Dindar for his important contribution to the analysis stage of this study with the software he developed.
Civil Engineer Ali Bayraktar and Hafez Keypour from SGM Construction provided required materials and contributed this research financially, which is highly appreciated.
Special thanks to my friends Tevfik Terzioğlu, Hasan Altun and Furkan Çelenli for their assistance and suggestions during the construction and testing of the specimens, and to the technicians, Hasan Şenel, Hamdi Ayar, Ümit Melep and Mesut Kardaş for their help in the experimental phase of this research.
I would like to thank my supervisors Ramiz Soylu and Tayfun Bayramkaya from SURYAPI End. Tic. A.Ş. for their patience and tolerance at work for the time required for this thesis to be completed.
Finally, I would like to thank my family and my love Ece Uçar for their continuous support and encouragement.
SEISMIC RETROFITTING OF UNREINFORCED LOAD BEARING BRICK WALLS IN HISTORIC BUILDINGS USING FIBER-REINFORCED POLYMER STRINGS Most of the historical buildings and monuments in the world are unreinforced masonry (URM) type and they are vulnerable to seismic actions. Considering the seismic activities in the regions where historical masonry structures are located, their structural assessment and rehabilitation or retrofitting if necessary against seismic forces are needed in order to preserve them for future generations. International organizations such as UNESCO (United Nations educational, Scientific and Cultural Organization) and ICOMOS (International Council on Monuments and Sites) try to increase the awareness in need for preserving these world-heritage structures. However, historical masonry structures still need retrofitting techniques that are much different than that of buildings that were built using conventional construction practice since the architectural features of the historic buildings must remain unchanged after the retrofitting process. Therefore, conventional methods have been used in retrofitting works are not suitable for such purposes. In this study, the use of carbon fiber-reinforced polymer (CFRP) strings placed in mortar joints for strengthening of URM structures was investigated. Nearly full-scaled four URM brick wall specimens with aspect ratio of 1.00 were tested under varying axial load and cyclic lateral loading. Two of the specimens were tested as control specimens while other two specimens were retrofitted with horizontally-oriented CFRP strings. Also, one of the tested control specimens were repaired and retrofitted and re-tested in order to see the effect of this retrofitting technique after substantial damage occurred. Test results showed that energy dissipation capacity of the wall specimens were enhanced with the proposed technique. In addition, the crack openings due to shear effects were minimized while keeping the historic and aesthetical view of the structures intact, since they were directly placed inside the mortar joints and debonding of strings were prevented. However, no significant increase in the lateral load carrying capacity of the specimens was observed.