Experimental Study on Axial Compression Behavior on Circular Timber Columns Strengthened with CFRP Strips and Near-Surface Mounted Steel Bars
Publication: Journal of Structural Engineering
Volume 147, Issue 3
Abstract
To investigate the working mechanism and reinforcement effectiveness of the ancient timber columns strengthened with carbon fiber reinforced polymer (CFRP) strips and near-surface mounted steel bars, in this paper, 42 timber columns have been tested under axial compression, which considered the arrangement modes of CFRP strips, number of near-surface mounted steel bars, and different strengthening ways as the main influencing factors. Based on the test results, failure modes of specimens and materials were analyzed, compressive bearing capacity and ultimate deformation of each specimen were obtained, and load-displacement curves of timber columns were diagramed. Moreover, the load-strain curves of specimens were obtained through the data collected using an extensometer, and the deformation compatibility performance of three different materials was evaluated according to the strain comparison. The test results indicate that the wrapped CFRP strips way and near-surface mounted method can work together to mutually boost the reinforcement effectiveness. The proposed composite reinforcement method can significantly improve the bearing capacity and deformation performance of timber columns. Moreover, the increase in the number of CFRP strips and steel bars generates a marked enhancement in timber columns’ compression performance. The load-strain curves of timber, steel bars, and CFRP strips are in good agreement, and the percentage differences of three different materials’ strains are almost lower than 20%, illustrating that three types of materials have acceptable deformation compatibility performance.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all of the data, models, or code that support the findings of this study are available from the corresponding author on reasonable request.
(1) Data in Table 6. Results of specimens; (2) Data in f Fig. 7. Axial load-displacement curves of specimens; (3) Data in Fig. 9. Axial load-strain curves of specimens; and (4) Data in Fig. 10. Strain comparison curves.
Acknowledgments
The authors are deeply grateful for the financial support from the National Natural Science Foundation of China (Grant Nos. 51678039 and 51478033).
References
Borri, A., M. Corradi, and A. Grazini. 2005. “A method for flexural reinforcement of old wood beams with CFRP materials.” Composites, Part B 36 (2): 143–153. https://doi.org/10.1016/j.compositesb.2004.04.013.
Broughton, J. G., and A. R. Hutchinson. 2001. “Pull-out behaviour of steel rods bonded into timber.” Mater. Struct. 34 (2): 100–109. https://doi.org/10.1007/BF02481558.
Chun, Q., Y. Zhang, and J. W. Pan. 2013a. “Experiment on axial compression properties of circular timber columns strengthened with near-surface mounted CFRP rods.” [In Chinese.] J. Archit. Civ. Eng. 30 (3): 20–24. https://doi.org/10.3969/j.issn.1673-2049.2013.03.004.
Chun, Q., Y. Zhang, and J. W. Pan. 2013b. “Experimental study on Mechanical properties of circular timber columns strengthened with near-surface mounted CFRP sheets under axial compression.” [In Chinese.] Ind. Constr. 43 (7): 91–95.
Eid, R., and P. Paultre. 2017. “Compressive behavior of FRP-confined reinforced concrete columns.” Eng. Struct. 132 (Feb): 518–530. https://doi.org/10.1016/j.engstruct.2016.11.052.
Garyfallia, G., et al. 2015. “Axially loaded reinforced concrete columns with a square section partially confined by light GFRP straps.” J. Compos. Constr. 19 (1): 04014035. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000496.
Gentile, C., D. Svecova, and S. Rizkalla. 2002. “Timber beams strengthened with GFRP bars: Development and applications.” J. Compos. Constr. 6 (1): 11–20. https://doi.org/10.1061/(ASCE)1090-0268(2002)6:1(11).
Li, H. M., H. X. Qiu, Z. Zhao, and Y. Lu. 2018. “Experimental study on splice-jointed timber columns reinforced with steel jackets.” [In Chinese.] J. Central South Univ. (Sci. Technol) 49 (1): 192–200. https://doi.org/10.11817/j.issn.1672-7207.2018.01.025.
Li, X. M., et al. 2009. “Experimental research on CFRP-strengthened old timber columns.” [In Chinese.] Earthquake Resistant Eng. Retrofitting. 31 (4): 55–59. https://doi.org/10.3969/j.issn.1002-8412.2009.04.011.
Ling, Z., H. Yang, W. Liu, W. Lu, D. Zhou, and L. Wang. 2014. “Pull-out strength and bond behaviour of axially loaded rebar glued-in glulam.” Constr. Build. Mater. 65 (Aug): 440–449. https://doi.org/10.1016/j.conbuildmat.2014.05.008.
Liu, C. W. 2011. Research on reinforcement technologies of wooden structure in villages and small towns. [In Chinese.] Wuhan, China: Huazhong Univ. of Science and Technology.
Ma, J. X., P. Hu, X. M. Jiang, and M. Hu. 2005. “Experimental research on axial compressive behaviors for timber columns strengthened with CFRP.” [In Chinese.] Ind. Constr. 35 (8): 40–44. https://doi.org/10.3321/j.issn:1000-8993.2005.08.009.
Nowak, T., J. Jasieńko, and D. Czepizak. 2013. “Experimental tests and numerical analysis of historic bent timber elements reinforced with CFRP strips.” Constr. Build. Mater. 40 (Mar): 197–206. https://doi.org/10.1016/j.conbuildmat.2012.09.106.
Raftery, G., and F. Kelly. 2015. “Basalt FRP rods for reinforcement and repair of timber.” Composites, Part B Eng. 70 (Mar): 9–19. https://doi.org/10.1016/j.compositesb.2014.10.036.
Raftery, G., and C. Whelan. 2014. “Low-grade glued laminated timber beams reinforced using improved arrangements of bonded-in GFRP rods.” Constr. Build. Mater. 52 (Feb): 209–220. https://doi.org/10.1016/j.conbuildmat.2013.11.044.
Shao, J. S., W. Q. Liu, T. Jiang, S. G. Wang, and D. Zhou. 2008. “Stress-strain model for FRP-strengthened wood column under axial compression.” [In Chinese.] Eng. Mech. 25 (2): 183–187.
Shao, J. S., W. Xue, W. Liu, J. Jiang, and T. Jiang. 2012. “Calculation of axial compressive behavior of timber column laterally strengthened with FRP.” [In Chinese.] China Civ. Eng. J. 45 (8): 48–54. https://doi.org/10.15951/j.tmgcxb.2012.08.022.
Standard Press of China. 2007. Steel for the reinforcement of concrete—Part 2: Hot rolled ribbed bars. [In Chinese.] GB 1499.2. Beijing: Standard Press of China.
Standard Press of China. 2009a. Method for determination of the density of wood. [In Chinese.] GB/T 1933. Beijing: Standard Press of China.
Standard Press of China. 2009b. Method for determination of the modulus of elasticity in static bending of wood. [In Chinese.] GB/T 1936.2. Beijing: Standard Press of China.
Standard Press of China. 2009c. Method for determination of the moisture content of wood. [In Chinese.] GB/T 1931. Beijing: Standard Press of China.
Standard Press of China. 2009d. Method of testing in compression perpendicular to grain of wood. [In Chinese.] GB/T 1939. Beijing: Standard Press of China.
Standard Press of China. 2009e. Method of testing in compressive strength parallel to grain of wood. [In Chinese.] GB/T 1935. Beijing: Standard Press of China.
Svecova, D., and R. J. Eden. 2004. “Flexural and shear strengthening of timber beams using glass fibre reinforced polymer bars—An experimental investigation.” Can. J. Civ. Eng. 31 (1): 45–55. https://doi.org/10.1139/l03-069.
Teng, J. G., Y. M. Hu, and T. Yu. 2013. “Stress-strain model for concrete in FRP-confined steel tubular columns.” Eng. Struct. 49 (2): 156–167. https://doi.org/10.1016/j.engstruct.2012.11.001.
Wang, J. H., et al. 2017a. “Experimental study of the mechanical properties of Xinjiang poplar rectangular section long columns under eccentric compression.” [In Chinese.] Ind. Constr. 47 (5): 85–89. https://doi.org/10.13204/j.gyjz201705017.
Wang, J. H., et al. 2017b. “Experimental study on the axial compression performance of the rectangular section columns strengthened by externally bonded BFRP in Xinjiang poplar.” [In Chinese.] Earthquake Resistant Eng. Retrofitting 39 (5): 123–128. https://doi.org/10.16226/j.issn.1002-8412.2017.05.017.
Wang, K. 2007. Experimental study of carbon fiber reinforced polymer (CFRP) reinforced the ancient wood buildings. [In Chinese.] Xi’an, China: Xi’an Univ. of Architecture and Technology.
Xie, Q. F. 2007. Experimental study and theoretical analysis on strengthening for Chinese ancient timber buildings. [In Chinese.] Xi’an, China: Xi’an Univ. of Architecture and Technology.
Xu, Q. F. 2012. “Experimental study of strengthening methods of partially-damaged circular wood columns.” [In Chinese.] J. Central South Univ. (Sci. Technol.) 43 (4): 307–314.
Xu, Q. F., and L. Zhu. 2007. “An experimental study on partially-damaged wood columns repaired and strengthened with CFRP.” [In Chinese.] China Civ. Eng. J. 40 (8): 41–46. https://doi.org/10.3321/j.issn:1000-131x.2007.08.007.
Zhang, D. Z. 2003. Study on the reinforcement and repairing performance of timber columns and beams with CFRP strips. [In Chinese.] Shanghai, China: Tongji Univ.
Zhang, X. T. 2016. The study of Huizhou traditional architecture wooden reinforcement and repairing methods. Hefei, China: Anhui Jianzhu Univ.
Zhang, Y. 2013. Experimental study on timber frame members strengthened with NSM CFRP materials. [In Chinese.] Nanjing, China: Southeast Univ.
Zhou, Q., et al. 2016a. “Axial compression experiments on timber columns strengthened with CFRP sheets on decay roots by coating reinforcing technique.” [In Chinese.] J. Hunan Univ. (Nat. Sci) 43 (3): 120–126. https://doi.org/10.3969/j.issn.1674-2974.2016.03.016.
Zhou, Q., and W. M. Yan. 2011. “Application of iron-strengthening techniques in Chinese ancient buildings.” [In Chinese.] J. Water Resour. Archit. Eng. 9 (1): 1–5. https://doi.org/10.3969/j.issn.1672-1144.2011.01.001.
Zhou, Q., N. Yang, and W. M. Yan. 2016b. “Experimental study on axial compression of timber columns strengthened by CFRP-Dunjie method on decay bottoms.” [In Chinese.] Supplement, J. Build. Struct. 37 (S1): 314–320. https://doi.org/10.14006/j.jzjgxb.2016.S1.044.
Zhou, Z. H. 2005. Research on the behavior of timber structural members strengthened with CFRP. [In Chinese.] Nanjing, China: Nanjing Univ. of Technology.
Zhu, L., et al. 2009. “Experimental research on short cracked timber columns strengthened with CFRP.” [In Chinese.] Build. Struct. 39 (11): 101–103. https://doi.org/10.19701/j.jzjg.2009.11.027.
Zhu, L., and Q. F. Xu. 2008. “Experimental research on behaviors of CFRP-reinforced timber columns.” [In Chinese.] Ind. Constr. 38 (12): 113–116. https://doi.org/10.13204/j.gyjz2008.12.019.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 147 • Issue 3 • March 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Jan 2, 2020
Accepted: Sep 29, 2020
Published online: Jan 5, 2021
Published in print: Mar 1, 2021
Discussion open until: Jun 5, 2021
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.