Abstract
Bonding fiber reinforced polymer (FRP) has been commonly used to improve the seismic behavior of circular reinforced concrete (RC) columns in engineering practice. However, FRP jackets have a significant stress hysteresis effect in this strengthening method, and pre-tensioning the FRP can overcome this problem. This paper presents test results of 25 circular RC columns strengthened with pre-stressed FRP strips under low cyclic loading. The pre-stressing of the FRP strips, types of FRP strips and longitudinal reinforcement, axial load ratio, pre-damage degree and surface treatments of the specimens are considered as the primary factors in the tests. According to the failure modes and hysteresis curves of the specimens, these factors are analyzed to investigate their effect on bearing capacity, ductility, hysteretic behavior, energy dissipation capacity and other important seismic behaviors. The results show that the initial lateral confined stress provided by pre-stressed FRP strips can effectively inhibit the emergence and development of diagonal shear cracks, and change the failure modes of specimens from brittle shear failure to bending or bending-shear failure with better ductility. As a result, the bearing capacity, ductility, energy dissipation capacity and deformation capacity of the strengthened specimens are all significantly improved.
Similar content being viewed by others
References
ACI 440.2R-08 (2008), “Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures,” ACI Committee 440, USA.
Andrawes B and Shin M (2009), “Experimental Investigation of Concrete Columns Wrapped with Shape Memory Alloy Spirals,” Improving the Seismic Performance of Existing Building and Other Structures, December 9–11, San Francisco, USA.
Baris B (2008), “Design of FRPs in Circular Bridge Column Retrofits for Ductility Enhancement,” Engineering Structures, Elsevier, 30: 766–776.
CECS 146 (2003), Technical Specification for Strengthening Concrete Structures with Carbon Fiber Reinforce a Polymer Laminate, Beijing: China Planning Press. (in Chinese)
Fei W, Jiang SY and Zeng XR (2006), “Experimental Research on Seismic Behavior of Reinforced Concrete Columns Strengthened with Carbon Fiber Sheets,” Journal of Logistical Engineering University, 4: 12–16. (in Chinese)
GB50010-2010 (2011), Code for Design of Concrete Structures, Beijing: China Architecture & Building Press, pp. 34–39. (in Chinese)
Gu DS, Wu G and Wu ZS (2010), “Ultimate Flexural Strength of Normal Section of FRP-confined RC Circular Columns,” Journal of Southeast University, 26(1): 107–111. (in Chinese)
Janke L, Czaderski C, Ruth J and Motavalli M (2009), “Experiments on the Residual Load-bearing Capacity of Pre-stresspre-stressed Confined Concrete Columns,” Engineering Structures, 31(10): 2247–2256.
Li Ji (2011), Design and Behavior Research on Self-Locking Anchor System of FRP, Beijing Jiaotong University, Beijing, China. (in Chinese)
Liu JX and Zhao GH (2009), “Typical Bridge Damage Analysis in “5·12” Wenchuan Earthquake,” Journa1 of Architecture and Civil Engineering, 26(2): 92–97. (in Chinese)
Masoud M, Christoph C and Kerstin PL (2011), “Prestressed CFRP for Strengthening of Reinforced Concrete Structures: Recent Developments at Empa, Switzerland,” Journal of Composite Construction, 15(2): 194–205.
Nesheli KN and Meguro K (2006), “Seismic Retrofitting of Earthquake-damaged Concrete Columns by Lateral Pre-tensioning of FRP Belts,” Proceedings of the 8th U.S. National Conference on Earthquake Engineering, April 18–22, San Francisco, California, USA.
Pantelides CP, Gergelv J, Reaveley LD et al. (1999), “Retrofit of RC Bridge Pier with CFRP Advanced Composites,” Journal of Structural Engineering, ASCE, 125(10): 1094–1099.
Shahab MT and Asghar VO (2007), “Experimental Investigation of FRP Relaxation and Its Effect on Prestressing Techniques,” 8th International Symposium on FRP Reinforcement for Concrete Structures, University of Patras, Patras, Greece.
Shahab MT and Hasan M (2007), “Experimental and Analytical Investigation of Square RC Columns Retrofitted with Pre-stressed FRP Strips,” 8th International Symposium on FRP Reinforcement for Concrete Structures, University of Patras, Patras, Greece.
Sheikh SA (2001), “Use of FRP Composites for Seismic Upgrade of Concrete Columns,” Proceedings of the International Conference on FRP Composites in Civil Engineering, II: 901–908, Hong Kong, China.
Sheikh SA (2002), “Performance of Concrete Structures Retrofitted with Fiber Reinforced Polymers,” Engineering Structures, Elsevier, 24: 869–879.
Wang W, Song K and Wang DP (2008), “Experimental Investigation on Seismic Performance of CFRP Retrofitted RC Short Columns with Circular Section,” World Information on Earthquake Engineering, 24(4): 96–100.
Xiao Y and Ma R (1997), “Seismic Retrofit of RC Circular Columns Using Prefabricated Composite Jacketing,” Journal of Structural Engineering, ASCE, 123(10): 1357–1364.
Xiao Y, Wu H and Martin GR (1999), “Prefabricated composite Jacketing of RC columns for Enhanced Shear Strength,” Journal of Structural Engineering, ASCE, 125(3): 255–264.
Yamakawa T, Nasrollahzadeh Nesheli K and Satoh H (2001), “Seismic or Emergency Retrofit of RC Short Columns by Use of Pre-stressed Aramid Fiber Belts as External Hoops,” Journal of Structural and Construction Engineering, AIJ, 550:135–141.
Zhao GT and Cao FB (2010), “Seismic Behavior of Reinforced Concrete Crack-short Columns Strengthened with CFRP,” Earthquake Resistant Engineering and Retrofitting, 32(5): 85–90. (in Chinese)
Zhou CD and Huang CK (2006), “Investigation on Seismic-resistance Behavior of Concrete Columns Strengthened with GFRP,” Journal of Harbin Institute of Technology, 38 (3): 427–431. (in Chinese)
Zhou CD, Zhao F, Zhang AR, et al. (2009), “The Mechanical Behavior of Concrete Pier Strengthened with Lateral Pre-stressed FRP Sheets,” Industrial Construction, 39(4): 124–127. (in Chinese)
Zhuang WL, Liu ZY and Jiang JI (2009), “Earthquakeinduced Damage Analysis of Highway Bridges in Wenchuan Earthquake and Countermeasures,” Chinese Journal of Rock Mechanics and Engineering, 28(7): 1377–1387. (in Chinese)
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by: National Natural Science Foundation of China under Grant No. 51178029; the State Key Laboratory for Disaster Reduction in Civil Engineering at Tongji University under Grant No. SLDRCE08-MB-01
Rights and permissions
About this article
Cite this article
Zhou, C., Lu, X., Li, H. et al. Experimental study on seismic behavior of circular RC columns strengthened with pre-stressed FRP strips. Earthq. Eng. Eng. Vib. 12, 625–642 (2013). https://doi.org/10.1007/s11803-013-0202-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11803-013-0202-0