Strengthening of Gulfport 230 kV Wooden Transmission Structures with Glass-Fiber-Reinforced Polymer Wrap
Publication: Journal of Composites for Construction
Volume 15, Issue 3
Abstract
This paper presents a statistically designed experimental program to present and analyze an effective and practical strengthening system for deteriorated crossarms of the Gulfport timber structures using glass-fiber-reinforced polymer (GFRP) wrap. In this research, a total of 14 strengthened and six control specimens with a length of approximately 3.1 m were tested to failure. The experimental program was conducted in two phases: feasibility study and parameter optimization designed by using the Taguchi method and analysis of variation (ANOVA). The feasibility study concluded that the proposed strengthening system was sufficient for increasing the strength of the deteriorated crossarms of the Gulfport structures well above the critical end-of-life (EOL) design threshold value of the crossarms. The parametric optimization of the strengthening system identified the critical variables to be the crack-repair material, the width of the wrap, and sanding the surface. Using statistical advantages of the Taguchi method of experimental design, the mean strength of the strengthened specimens was estimated, and a 95% confidence interval for that mean was calculated. This estimated mean was 70% higher than the EOL threshold of the crossarms.
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Acknowledgments
The writers would like to acknowledge the technical assistance of Mr. Mark Crozier, Sika Canada Inc. The financial support of the Natural Sciences and Engineering Research Council of Canada is appreciated.
References
Ahmed, M. R., and Lyons, J. S. (2005). “Factors affecting the bond between polymer composites and wood.” J. Reinf. Plast. Compos., 24(4), 405–412.
American Concrete Institute (ACI). (2007). “Report on fiber-reinforced polymer (FRP) reinforcement for concrete structures.” ACI 440R-07, Farmington Hills, MI.
Bendell, A., Disney, J., and Pridmore, W. A. (1989). Taguchi methods: Applications in world industry, IFS Publications, UK.
Bonacci, J. F., Hearn, N., Pantazopoulou, S. J., Sheikh, S., and Thomas, M. D. A. (2001). “Repair of corrosion-damaged columns with FRP wraps.” J. Compos. Constr., 5(1), 3–11.
Borri, A., Corradi, M., and Grazini, A. (2005). “A method for flexural reinforcement of old wood beams with CFRP materials.” Composites, Part B, 36(2), 143–153.
Canadian Standards Association (CSA). (2001). CSA C22.3 No. 1-01, Overhead Systems, Toronto.
Chahrour, A. H., and Soudki, K. A. (2006). “Structural retrofitting of deteriorated concrete lighting poles using FRP sheets in wet layup-field application.” J. Compos. Constr., 10(3), 234–243.
Davalos, J. F., Qiao, P. Z., and Trimble, B. S. (2000a). “Fiber-reinforced composite and wood bonded interface. Part 1: Durability and shear strength.” J. Compos. Technol. Res., 22(4), 224–231.
Davalos, J. F., Qiao, P. Z., and Trimble, B. S. (2000b). “Fiber-reinforced composite and wood bonded interface. Part 2: Fracture.” J. Compos. Technol. Res., 22(4), 232–240.
Davalos, J. F., Qiao, P., and Zipfel, M. G. (1999). “Feasibility study of prototype GFRP-reinforced wood railroad crosstie.” J. Compos. Constr., 3(2), 92–99.
Gilbert, S. G., Gilfillan, J. R., and Patrick, G. R. H. (2003). “The use of FRP composites in enhancing the structural behavior of timber beams.” J. Reinf. Plast. Compos., 22(15), 1373–1388.
Institute of Electrical and Electronics Engineers (IEEE). (1993). National Electrical Safety Code (NESC), C2-1993, New York.
McCarthy, F. J. (2005). “Condition assessment of wooden crossarms in 230 KV transmission structures.” M.Sc. thesis, Univ. of Waterloo, Waterloo, ON, Canada.
Nanni, A., and Norris, M. S. (1995). “FRP jacketed concrete under flexure and combined flexure-compression.” Constr. Build. Mater., 9(5), 273–281.
Shahi, A. (2008). “Strengthening of wooden crossarms in 230 kV transmission structures using glass fiber reinforced polymer (GFRP) wrap.” M.Sc. thesis, Univ. of Waterloo, Waterloo, ON, Canada.
Sika. (2008). Sika AnchorFix-3 CA product data sheets, Edition 11.2008, Sika Canada Inc., Pointe-Claire, QC, Canada.
Sika. (2009). SikaWrap Hex 100G and Hex 103C product data sheets, Edition 05.2009, Sika Canada Inc., Pointe-Claire, QC, Canada.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 15 • Issue 3 • June 2011
Pages: 364 - 373
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Dec 23, 2009
Accepted: Sep 2, 2010
Published online: Sep 7, 2010
Published in print: Jun 1, 2011
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