Title:
Flexural Behavior of Columns Strengthened Using Reinforced Concrete Jacket with Seismic Details
Author(s):
Keun-Hyeok Yang, Yong-Ha Hwang, Seung-Jun Kwon, and Ju-Hyun Mun
Publication:
Structural Journal
Volume:
117
Issue:
5
Appears on pages(s):
121-132
Keywords:
columns; ductility; flexural capacity; jacketing; prefabricated bar unit
DOI:
10.14359/51724669
Date:
9/1/2020
Abstract:
The primary objective of the present study is to examine the effectiveness of previously developed prefabricated bar units with seismic details in the jacket section in improving the flexural performance of columns jacketed with reinforced concrete (RC) sections. One non-seismic existing column, two bonded-type laminate-jacketed columns, and six RC-jacketed columns were tested under constant axial load and cyclic lateral loads. The flexural strength of the columns was examined by comparing with predictions obtained using the ACI 318-14 procedure and nonlinear section lamina analysis considering the confinement effect provided by the jacket. The flexural ductility of RC jacketed columns was assessed by using the work damage indicator and the performance-based approach proposed by Sheikh and Khoury for seismic virgin columns. The test results revealed that the proposed RC jacketing approach using prefabricated bar units has the potential to enhance the flexural stiffness, strength, and ductility of deficient columns by providing a reliable confinement. The flexural capacity of jacketed columns can be conservatively estimated by the ACI 318-14 procedure and predicted more accurately by the section lamina analysis. In addition, RC-jacketed columns with prefabricated bar units can be designed to possess moderate ductility performance by adjusting the amount of transverse reinforcement in the jacketed section.
Related References:
1. Thermou, G. E.; Papanikolaou, V. K.; and Kappos, A. J., “Flexural Behavior of Reinforced Concrete Jacketed Columns under Reversed Cycling Loading,” Engineering Structures, V. 76, 2014, pp. 270-282. doi: 10.1016/j.engstruct.2014.07.013
2. Vandoros, K. G., and Dritsos, S. E., “Concrete Jacket Construction Detail Effectiveness when Strengthening RC Columns,” Construction and Building Materials, V. 22, No. 3, 2008, pp. 264-276. doi: 10.1016/j.conbuildmat.2006.08.019
3. Sichko, A., and Sezen, H., “Review of Methods for Reinforced Concrete Column Retrofit,” SMAR 2017-Fourth Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures, Zürich, Switzerland, 2017.
4. 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
5. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 519 pp.
6. Takeuti, A. R.; de Hanai, J. B.; and Mirmiran, A., “Preloaded RC Columns Strengthened with High-Strength Concrete Jackets under Uniaxial Compression,” Materials and Structures, V. 41, No. 7, 2008, pp. 1251-1262. doi: 10.1617/s11527-007-9323-0
7. Júlio, E. N. B.; Franco, F. A. B.; and Silva, V. D., “Reinforced Concrete Jacketing-Interface Influence on Monotonic Loading Response,” ACI Structural Journal, V. 102, No. 2, Mar.-Apr. 2005, pp. 252-257.
8. Ha, G. J., and Seo, S. Y., “Experimental Study on the Retrofit Method to Improve the Structural Capacity of Reinforced Concrete Shear Wall,” Journal of the Korea Institute for Structural Maintenance and Inspection, V. 12, No. 4, 2008, pp. 79-86. (in Korean)
9. Shin, Y. S.; Hong, G. S.; Choi, O. C.; and Park, J. H., “An Experimental Studies on Structural Behavior of Reinforced Concrete Beam-Columns with Enlarged Cross Sections,” Journal of the Korea Institute for Structural Maintenance and Inspection, V. 1, No. 2, 1997, pp. 141-150. (in Korean)
10. Minafò, G., “A Practical Approach for the Strength Evaluation of RC Columns Reinforced with RC Jackets,” Engineering Structures, V. 85, 2015, pp. 162-169. doi: 10.1016/j.engstruct.2014.12.025
11. Yang, K. H., “Axial Behavior of Reinforced Concrete Columns Strengthened with New Section Enlargement Approaches,” ACI Structural Journal, V. 116, No. 5, Sept. 2019, pp. 87-96. doi: 10.14359/51715631
12. Sheikh, S. A., and Khoury, S. S., “A Performance-Based Approach for the Design of Confining Steel in Tied Columns,” ACI Structural Journal, V. 94, No. 4, July-Aug. 1997, pp. 421-431.
13. Yang, K. H., and Kim, W. W., “Axial Compression Performance of Reinforced Concrete Short Columns with Supplementary V-Shaped Ties,” ACI Structural Journal, V. 113, No. 6, Nov.-Dec. 2016, pp. 1347-1356. doi: 10.14359/51689159
14. Yang, K. H.; Kwak, M. K.; and Sim, J. I., “Flexural Behavior of Reinforced Concrete Columns with Supplementary V-Shaped Ties,” ACI Structural Journal, V. 114, No. 5, Sept.-Oct. 2017, pp. 1177-1188. doi: 10.14359/51700781
15. Kwon, H. J.; Yang, K. H.; and Sim, J. I., “Proposals of Reliable Shapes of Supplementary V-Ties for Section Jacketing Method of Columns,” Journal of the Korea Institute of Building Construction, V. 18, No. 2, 2018, pp. 99-107. (in Korean)
16. Lee, K. I.; Yoon, H. S.; and Yang, K. H., “Compressive and Adhesive Strengths of Mortars using Polymer and Ultra-Rapid-Hardening Cement,” Journal of the Korea Institute of Building Construction, V. 18, No. 4, 2018, pp. 329-335.
17. FEMA 356, “Prestandard and Commentary for the Seismic Rehabilitation of Buildings,” Federal Emergency Management Agency, Washington, DC, 2000, 516 pp.
18. 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.
19. Park, R., and Paulay, T., Reinforced Concrete Structures, Wiley Interscience, New York, 1975, 800 pp.
20. Priestley, M. N., and Park, R., “Strength and Ductility of Concrete Bridge Columns under Seismic Loading,” ACI Structural Journal, V. 84, No. 1, Jan.-Feb. 1987, pp. 61-76.
21. Yang, K. H.; Mun, J. H.; Cho, M. S.; and Kang, T. H. K., “A Stress-Strain Model for Various Unconfined Concrete in Compression,” ACI Structural Journal, V. 111, No. 4, July-Aug. 2014, pp. 819-826.
22. Kim, W. W.; Mun, J. H.; and Yang, K. H., “Simplified Model for the Stress-Strain Relationship of Confined Concrete,” Journal of the Architectural Institute of Korea: Structure & Construction, V. 31, No. 4, 2015, pp. 79-86. doi: (in Korean)10.5659/JAIK_SC.2015.31.4.79