Behavior of Tendons with Multiple CFRP Rods
Publication: Journal of Structural Engineering
Volume 142, Issue 10
Abstract
Research works related to the fiber-reinforced polymer (FRP) tendons have focused on the anchor system, but the anchor is not the only contribution to performance. Since civil structures require tendons consisting of multiple rods (e.g., cables, suspenders in bridges, or rock bolts in ground anchors), the characteristics of multirod tendons require targeted research. This paper presents a study on the behavior of tendons with multiple carbon FRP (CFRP) rods. Four specimens including two cable-type assemblies (TA12-9 and TA12-20) and two ground anchors (GA12-9 and GA12-20) with large-tonnage capacities were built and tested. Using strain gauges set along individual rods, the nonuniform force distribution among individual rods was observed and is discussed. The test results showed that nonuniformity is a recurring feature of a multirod tendon, with the variation in the initial length of the rods caused by installation error as its main reason. Based on the premise that tension in multiple rods obeys a normal distribution, the relationship between the nonuniformity coefficient, , and a corresponding capacity reduction coefficient, , was established. The tendon consisting of nine CFRP rods in TA12-9 (GA12-9) shows a capacity reduction factor of 0.83 (0.89), while the capacity reduction factor of the tendon consisting of 20 rods in TA12-20 (GA12-20) decreases to values of 0.79 (0.87).
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (Grant No. 51078134).
References
ACI (American Concrete Institute). (2014). “Building code requirements for structural concrete and commentary.” ACI 318M-14, Farmington Hills, MI.
ACI (American Concrete Institute). (2015). “Guide for the design and construction of concrete reinforced with FRP bars.” ACI 440.1R-15, Farmington Hills, MI.
Amaniampong, G., and Burgoyne, C. J. (1995). “Analysis of the tensile strength of parallel-lay ropes and bundles of parallel elements by probability theory.” Int. J. Solids Struct., 32(24), 3573–3588.
ASTM. (2008). “Standard test methods for laboratory determination of rock anchor capacities by pull and drop tests.” ASTM D7401-08, West Conshohocken, PA.
ASTM. (2013). “Standard test method for rock bolt anchor pull test.” ASTM D4435-13e1, West Conshohocken, PA.
Benmokrane, B., Xu, H., and Nishizaki, I. (1997). “Aramid and carbon fibre-reinforced plastic prestressed ground anchors and their field applications.” Can. J. Civ. Eng., 24(6), 968–985.
BSI (British Standards Institution). (2013). “Execution of special geotechnical works: Ground anchors.” BS EN 1537, London.
Burgoyne, C. J. (1993). “Parafil ropes for prestressing applications.” Fibre reinforced plastic (FRP) for concrete structures: Properties and applications, A. Nanni, ed., Elsevier Science, New York, 333–351.
Campbell, T. I., Shrive, N. G., Soudki, K. A., Al-Mayah, A., Keatley, J. P., and Reda, M. M. (2000). “Design and evaluation of a wedge-type anchor for fibre reinforced polymer tendons.” Can. J. Civ. Eng., 27(5), 985–992.
CECS (China Association for Engineering Construction Standardization). (2005). “Technical specification for ground anchors.” CECS 22-2005, Beijing.
CECS (China Association for Engineering Construction Standardization). (2015). “Reactive powder concrete.” GB/T 31387-2015, Beijing.
Chen, M., et al. (2011). “Large-scale ground anchorage system with high performance materials.” Proc., 28th Annual Int. Bridge Conf., Engineers’ Society of Western Pennsylvania, Pittsburgh, 694–699.
Committee on Cable-Stayed Bridges. (2014). Guidelines for the design of cable-stayed bridges, M. C. Tang and C. C. Ulstrup, eds., ASCE, Reston, VA.
Cosenza, E., Manfredi, G., and Realfonzo, R. (1997). “Behavior and modeling of bond of FRP rebars to concrete.” J. Compos. Constr., 40–51.
Daniels, H. E. (1945). “The statistical theory of the strength of bundles of threads. I.” Proc. R. Soc. London A: Math. Phys. Eng. Sci., 183(995), 405–435.
Erki, M. A., and Rizkalla, S. (1993). “Anchorages for FRP.” Concr. Int., 15(6), 54–59.
Faber, M. H., Engelund, S., and Rackwitz, R. (2003). “Aspects of parallel wire cable reliability.” Struct. Saf., 25(2), 201–225.
Fang, Z., Zhang, K., and Tu, B. (2013). “Experimental investigation of a bond-type anchorage system for multiple FRP tendons.” Eng. Struct., 57(1), 364–373.
Feylessoufi, A., Villieras, F., Michot, L. J., De Donato, P., Cases, J. M., and Richard, P. (1996). “Water environment and nanostructural network in a reactive powder concrete.” Cem. Concr. Compos., 18(1), 23–29.
Holte, L. E., Dolan, C. W., and Schmidt, R. J. (1993). “Epoxy socketed anchors for nonmetallic prestressing tendons.” Fibre-Reinforced-Plastic Reinforcement for Concrete Structures Int. Symp. SP 138, American Concrete Institute, Detroit, 381–400.
Machida, A. (1993). “State-of-the-art report on continuous fiber reinforcing materials.” Research Committee on Continuous Fiber Reinforcing Materials, Japan Society of Civil Engineers, Tokyo.
Maljaars, J., and Vrouwenvelder, T. (2014). “Fatigue failure analysis of stay cables with initial defects: Ewijk Bridge case study.” Struct. Saf., 51, 47–56.
Malvar, L. J., and Bish, J. (1995). “Grip effects in tensile testing of FRP bars.” Proc., 2nd Int. RILEM Symp. FRPRCS-2, Ghent, E & FN, London, 108–115.
Matteo, J., Deodatis, G., and Billington, D. P. (1994). “Safety analysis of suspension-bridge cables: Williamsburg Bridge.” J. Struct. Eng., 3197–3211.
Meier, U. (2012). “Carbon fiber reinforced polymer cables: Why? Why Not? What If?” Arab. J. Sci. Eng., 37(2), 399–411.
Micelli, F., and Nanni, A. (2003). “Tensile characterization of FRP rods for reinforced concrete structures.” Mech. Compos. Mater., 39(4), 293–304.
Ministry of Water Resources of the People’s Republic of China. (2012). “Design specification for hydraulic prestressed anchorage.” SL212-12, Beijing.
MOT (Ministry of Transport of the People’s Republic of China). (2007). “Guidelines for design of highway cable-stayed bridge.” JTG/T D65-01-2007, Beijing.
Nanni, A., Bakis, C. E., O’Neil, E. F., and Dixon, T. O. (1996). “Performance of FRP tendon-anchorage systems for prestressed concrete structures.” PCI J., 41(1), 34–44.
Pitt, R. E., and Phoenix, S. L. (1981). “On modelling the statistical strength of yarns and cables under localized load-sharing among fibers.” Text. Res. J., 51(6), 408–425.
PTI (Post-Tensioning Institute). (2012). “Recommendations for stay cable design, testing and installation.” PTI DC45.1-2012, Farmington Hills, MI.
Richard, P. (1995). “Composition of reactive powder concrete.” Cem. Concr. Res., 25(7), 1501–1511.
Sayed-Ahmed, E. Y., and Shrive, N. G. (1998). “A new steel anchorage system for post-tensioning applications using carbon fibre reinforced plastic tendons.” Can. J. Civ. Eng., 25(1), 113–127.
Wagner, H. D. (1989). “Stochastic concepts in the study of size effects in the mechanical strength of highly oriented polymeric materials.” J. Polym. Sci. Part B: Polym. Phys., 27(1), 115–149.
Zang, H., Tu, Y. M., Mei, K. H., and Zhang, W. (2010). “Research on the key problems of CFRP cables for cable-stayed bridges.” Proc., 10th Int. Conf. of Chinese Transportation Professionals (ICCTP), ASCE, Reston, VA, 3322–3329.
Zhang, B., and Benmokrane, B. (2004). “Design and evaluation of a new bond-type anchorage system for fiber reinforced polymer tendons.” Can. J. Civ. Eng., 31(1), 14–26.
Zhang, B., and Benmokrane, B. (2005). “Large model test of prestressed carbon fibre reinforced polymer ground anchors.” Can. J. Civ. Eng., 32(6), 1064–1074.
Zhang, K., Fang, Z., Nanni, A., Hu, J., and Chen, G. (2015). “Experimental study of a large-scale ground anchor system with FRP tendon and RPC grout medium.” J. Compos. Constr., 04014073.
Zhuge, P, Ye, H, Qiang, S., and Liu, M. (2011). “Experiment investigation and mechanical behavior analysis of multiple CFRP tendons anchorage system.” Eng. Mech., 28(7), 165–179 (in Chinese).
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 142 • Issue 10 • October 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Nov 9, 2014
Accepted: Feb 8, 2016
Published online: Apr 15, 2016
Discussion open until: Sep 15, 2016
Published in print: Oct 1, 2016
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.