Title:
Seismic Strengthening of Shear Walls Using Wire Ropes as Lateral Reinforcement
Author(s):
Keun-Hyeok Yang, Hyuck-Jin Kwon, and Seung-Jun Kwon
Publication:
Structural Journal
Volume:
115
Issue:
3
Appears on pages(s):
837-847
Keywords:
ductility; jacket section; lateral reinforcement; seismic strengthening; shear wall; wire rope
DOI:
10.14359/51701148
Date:
5/1/2018
Abstract:
This study proposed a practical strengthening technique for enhancing the seismic behavior of reinforced concrete shear walls using prestressed wire ropes as a lateral reinforcement at the wall boundary elements. An unstrengthened wall and six strengthened walls were tested under constant axial load and cyclic lateral loads to explore the significance and feasibility of the developed seismic-strengthening procedure. The main variables investigated were the amount of wire rope and height of the jacket section for strengthening. Test results revealed that the shear walls strengthened with wire ropes in their boundary elements had better buckling resistance of longitudinal reinforcement and ductility behavior than the non-seismic shear wall. Unlike the brittle behavior of the unstrengthened wall, the strengthened walls exhibited a highly enhanced ductile pattern in a lateral load—lateral displacement relationship. Thus, the strengthened walls achieved the displacement ductility ratio capacity required for the design of a medium ductility shear wall. In particular, the strengthened wall with a lateral reinforcement index of 0.174 met the minimum displacement ductility ratio requirement for a highly ductile shear wall. Considering the enhanced flexural behavior, including the strength, stiffness, and ductility, along with the construction efficiency, a recommendation could be made that the height of the jacket section when strengthening shear walls not exceed 0.76 times the wall height. Ultimately, the developed strengthening approach showed significant potential in enhancing the flexural stiffness, strength, and ductility of existing non-seismic shear walls.
Related References:
1. MacGregor, J. G., and Wight, J. K., Reinforced Concrete: Mechanics and Design, Pearson Education, Upper Saddle River, NJ, 2005, 1314 pp.
2. Massone, L. M., and Wallace, J. W., “Load-Deformation Response of Slender Reinforced Concrete Wall,” ACI Structural Journal, V. 101, No. 1, Jan.-Feb. 2004, pp. 103-113.
3. Christidis, K. I.; Vougioukas, E.; and Trezos, K. G., “Strengthening of Non-Conforming RC Shear Walls Using Different Steel Configurations,” Engineering Structures, V. 124, 2016, pp. 258-268. doi: 10.1016/j.engstruct.2016.05.049
4. Bohl, A., and Adebar, P., “Plastic Hinge Lengths in High-Rise Concrete Shear Walls,” ACI Structural Journal, V. 108, No. 2, Mar.-Apr. 2011, pp. 148-157.
6. Farvashany, F. E.; Foster, S. J.; and Rangan, B. V., “Strength and Deformation of High-Strength Concrete Shear Walls,” ACI Structural Journal, V. 105, No. 1, Jan.-Feb. 2008, pp. 21-29.
7. Kotsovos, G. M.; Cotsovos, D. M.; Kotsovos, M. D.; and Kounadis, A. N., “Seismic Behavior of RC Walls: An Attempt to Reduce Reinforcement Congestion,” Magazine of Concrete Research, V. 63, No. 4, 2011, pp. 235-246. doi: 10.1680/macr.10.00001
8. Wallace, J. W., “Seismic Design of RC Structural Walls. Part I: New Code Format,” Journal of Structural Engineering, ASCE, V. 121, No. 1, 1995, pp. 75-87. doi: 10.1061/(ASCE)0733-9445(1995)121:1(75)
9. Wallace, J. W., and Orakcal, K., “ACI 318-99 Provisions for Seismic Design of Structural Walls,” ACI Structural Journal, V. 99, No. 4, July-Aug. 2002, pp. 499-508.
10. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 520 pp.
11. The European Standard EN 1998-1:2004, Eurocode 8: Design of Structures for Earthquake Resistance, British Standards Institution, London, UK, 2004, 229 pp.
12. Arya, C.; Clarke, J. L.; Kay, E. A.; and O’Regan, P. D., “TR 55: Design Guidance for Strengthening Concrete Structures Using Fibre Composite Materials: A Review,” Engineering Structures, V. 24, No. 7, 2002, pp. 889-900. doi: 10.1016/S0141-0296(02)00027-5
13. Shen, D.; Yang, Q.; Jiao, Y.; Cui, Z.; and Zhang, J., “Experimental Investigations on Reinforced Concrete Shear Walls Strengthened with Basalt Fiber-Reinforced Polymers under Cyclic Load,” Construction and Building Materials, V. 136, 2017, pp. 217-229. doi: 10.1016/j.conbuildmat.2016.12.102
14. Le Nguyen, K.; Brun, M.; Limam, A.; Ferrier, E.; and Michel, L., “Pushover Experiment and Numerical Analyses on CFRP-Retrofit Concrete Shear Walls with Different Aspect Ratios,” Composite Structures, V. 113, 2014, pp. 403-418. doi: 10.1016/j.compstruct.2014.02.026
15. Altin, S.; Kopraman, Y.; and Baran, M., “Strengthening of RC Walls Using Externally Bonding of Steel Strips,” Engineering Structures, V. 49, 2013, pp. 686-695. doi: 10.1016/j.engstruct.2012.12.022
16. Sim, J. I., and Yang, K. H., “Flexural Behavior of Reinforced Concrete Columns Strengthened with Wire Rope and T-Plate Units,” ACI Structural Journal, V. 106, No. 5, Sept.-Oct. 2009, pp. 697-708.
17. Marini, A., and Meda, A., “Retrofitting of R/C Shear Walls by Means of High Performance Jackets,” Engineering Structures, V. 31, No. 12, 2009, pp. 3059-3064. doi: 10.1016/j.engstruct.2009.08.005
18. Yang, K. H., “Flexural Behaviour of RC Columns Using Wire Ropes as Lateral Reinforcement,” Magazine of Concrete Research, V. 64, No. 3, 2012, pp. 269-281. doi: 10.1680/macr.10.00191
19. Mun, J. H.; Yang, K. H.; and Lee, Y., “Seismic Tests on Heavyweight Concrete Shear Walls with Wire Ropes as Lateral Reinforcement,” ACI Structural Journal, V. 113, No. 4, July-Aug. 2016, pp. 665-675. doi: 10.14359/51688615
20. Sheikh, S. A., and Khoury, S. S., “Confined Concrete Columns with Stubs,” ACI Structural Journal, V. 90, No. 4, July-Aug. 1993, pp. 414-431.
21. Sim, J. I.; Yang, K. H.; and Shim, H. J., “Test on Seismic Strengthening of RC Columns Using Wire Rope and T-Plate Units,” Magazine of Concrete Research, V. 61, No. 10, 2009, pp. 823-836. doi: 10.1680/macr.2008.61.10.823
22. ASTM A416/A416M-12, “Standard Specification for Steel Strand, Uncoated Seven-Wire for Prestressed Concrete,” ASTM International, West Conshohocken, PA, 2012, 8 pp.