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Title	Seismic evaluation and rehabilitation of reinforced concrete bridge wall piers
Publication Type	thesis
School or College	College of Engineering
Department	Civil & Environmental Engineering
Author	Kunwar, Bhaskar
Date	2019
Description	This study presents a rapid rehabilitation technique to repair and retrofit damaged and seismically deficient reinforced concrete bridge wall piers. The study consists of two half-scale specimens with three experimental tests. The first specimen is a control specimen called code compliant, designed and constructed based on the current American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LFRD) guidelines. The second specimen called as-built specimen, built with the seismic deficiencies such as lap splices in the plastic hinge region, low transverse and longitudinal reinforcements, and lack of seismic detailing present in old as-built reinforced concrete bridge wall piers. The tested code compliant specimen ultimately failed by dissipating a large amount of hysteretic energy. A successful repair of the damaged code compliant wall pier specimen was performed using the plastic hinge relocation technique. This repair consisted of prefabricated carbon fiber reinforced polymer shells, epoxy anchored headed steel bars, steel studs embedded steel collar, and expansive cement grout to strengthen the damaged region and relocate the plastic hinge in the wall pier to a minor damage region. The repaired specimen was retested with the quasi-static reverse cyclic lateral load to check the effectiveness of the repair. A rapid retrofit technique with the fiber composites was developed to strengthen (i.e., increase the flexural, shear, and bond strength) of the seismically deficient old as-built iv reinforced concrete bridge wall piers. This method uses Near Surface Mounted (NSM) technique with carbon fiber rod in combination with the Carbon Fiber Reinforced Polymer (CFRP) sheets and CFRP horizontal anchors. The horizontal anchors were used to provide the bond strength to the lap splices present whereas the NSM rods were installed to increase the flexural capacity of the wall. The CFRP wrap increases the confinement and prevents the premature buckling of the NSM bars. In order to check the effectiveness of the rehabilitation, a comparison study was made with the obtained experimental data. The repair method applied for the damaged code compliant specimen successfully relocated the plastic hinge and restored both the stiffness and load carrying capacity. The proposed retrofitting method for the as-built specimen also significantly improved the stiffness, flexural as well as energy dissipating capacity.
Type	Text
Publisher	University of Utah
Dissertation Name	Master of Science
Language	eng
Rights Management	© Bhaskar Kunwar
Format	application/pdf
Format Medium	application/pdf
ARK	ark:/87278/s60k87p8
Setname	ir_etd
ID	1696231
Reference URL	https://collections.lib.utah.edu/ark:/87278/s60k87p8

Page Metadata

Title	Page 191
Format	application/pdf
Setname	ir_etd
ID	1696422
OCR Text	Show 181 systems.html> (Nov. 27, 2018). Faustino, P., and Chastre, C. (2016). “Damage effect on concrete columns confined with carbon composites.” ACI Structural Journal, 113(5), 951–962. Galati, D., and De Lorenzis, L. (2009). “Effect of construction details on the bond performance of NSM FRP bars in concrete.” Advances in Structural Engineering, 12(5), 683–700. Ghosh, K. K., and Sheikh, S. A. (2007). “Seismic upgrade with carbon fiberreinforcedpolymer of columns containing lap-spliced reinforcing bars.” ACI Structural Journal. Hantouche, E. G., Harajli, M., Haddadin, F., and Elsouri, A. (2015). “Seismic strengthening of bond-critical regions in wall-type bridge piers using active confinement.” Journal of Bridge Engineering, 20(11), 1–12. Harajli, M. H. (2009). “Bond strengthening of lap spliced reinforcement using external FRP jackets: An effective technique for seismic retrofit of rectangular or circular RC columns.” Construction and Building Materials. Harajli, M. H., and Dagher, F. (2008). “Seismic strengthening of bond-critical regions in rectangular reinforced concrete columns using fiber-reinforced polymer wraps.” ACI Structural Journal. Harries, K. A., Ricles, J. R., Pessiki, S., and Sause, R. (2006). “Seismic retrofit of lap splices in nonductile square columns using carbon fiber-reinforced jackets.” ACI Structural Journal. J.F.Chen & J.G.Teng. (2001). “Anchorage strength models for FRP and steel plates bonded to concrete.” Journal of Structural Engineering, 127(c), 784–791. Jiang, S. F., Zeng, X., Shen, S., and Xu, X. (2016). “Experimental studies on the seismic behavior of earthquake-damaged circular bridge columns repaired by using combination of near-surface-mounted BFRP bars with external BFRP sheets jacketing.” Engineering Structures, 106, 317–331. Kim, I. S., Jirsa, J. O., and Bayrak, O. (2011). “Use of carbon fiber-reinforced polymer anchors to repair and strengthen lap splices of reinforced concrete columns.” ACI Structural Journal, 108(5), 630–640. Mahini, S. S., and Ronagh, H. R. (2011). “Web-bonded FRPs for relocation of plastic hinges away from the column face in exterior RC joints.” Composite Structures, Elsevier Ltd, 93(10), 2460–2472. Mander, J. B., and Priestley, M. J. N. (1989). “Theoretical stress-strain model for confined concrete.” Journal of Structural Engineering, 114(8), 1804-1826.
Reference URL	https://collections.lib.utah.edu/ark:/87278/s60k87p8/1696422