Effects of Diameter on the Durability of Glass Fiber–Reinforced Polymer Bars Conditioned in Alkaline Solution
Publication: Journal of Composites for Construction
Volume 21, Issue 5
Abstract
Current standards do not consider the diameter of glass fiber-reinforced polymer (GFRP) bars used as internal reinforcement in concrete structures to be a factor influencing bar durability. This paper investigates the effects of bar diameter on the physical and mechanical properties as well as the durability of GFRP reinforcing bars conditioned for three months at 60°C in an alkaline solution simulating a concrete environment. Five diameters (nominal diameters of 9.5, 12.7, 15.9, 19.1, and 25.4 mm) were considered; bar properties were assessed before and after conditioning. Microstructural analyses and measurement of physicochemical properties were also carried out. The results show that bar size had no significant effect on bar physical properties, except for water absorption. The smaller diameter bars had higher water absorption than the larger ones because of their higher surface area-to-volume ratios. In the case of the unconditioned bars, the tensile strength and modulus were not significantly affected by bar diameter, but there was a size effect for interlaminar shear strength and flexural strength. Conversely, the conditioning in the alkaline solution had a greater negative effect on the tensile strength of the larger bars than on the smaller ones. Scanning electron microscope (SEM) observations and Fourier transform infrared spectroscopy (FTIR) analysis revealed that the degradation remained at the surface of all the conditioned specimens. Nevertheless, there were only small variations between the physical and mechanical properties of the GFRP bars of different diameters. This indicates that the current provisions in standards that do not relate strength retention limit to bar size are acceptable.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), NSERC Research Chair in Innovative FRP Reinforcement for Concrete Infrastructures, the Fonds Québécois de la Recherche sur la Nature et les Technologies (FQR-NT), and Pultrall, Inc. (Thetford Mines, Quebec) for the GFRP materials support. The technical assistance from the staff of the structural laboratory in the department of civil engineering, faculty of engineering at the University of Sherbrooke, are also acknowledged. The second author also acknowledges the scholarship granted by the Australian Government Endeavour Research Fellowships to undertake his research and professional development at the University of Sherbrooke.
References
ACI (American Concrete Institute). (2008). “Metric specification for carbon and glass fiber-reinforced polymer bar materials for concrete reinforcement.” ACI-440.6M-08, Farmington Hills, MI.
ACI (American Concrete Institute). (2012). “Guide test methods for fiber-reinforced polymer.” ACI 440.3R-12, 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.
Ahmed, E., Benmokrane, B., and Sansfaçon, M. (2016). “Case study: Design, construction, and performance of the La Chancelière parking garage’s concrete flat slabs reinforced with GFRP bars.” J. Compo. Constr., 05016001.
Arafa, A., Farghaly, A., Ahmed, E., and Benmokrane, B. (2016). “Testing of GFRP-RC panels with UHPRFC joints of Nipigon river cable stayed bridge in northwest Ontario, Canada.” J. Bridge Eng., 05016006.
Archillides, Z., and Pilakoutas, K. (2004). “Bond behavior of fiber reinforced polymer bars under direct pullout conditions.” J. Compos. Constr., 173–181.
ASTM. (2009). “Standard test method for dye penetration of solid fiberglass reinforced pultruded stock.” ASTM D5117-09, West Conshohocken, PA.
ASTM. (2010). “Standard test method for water absorption of plastics.” ASTM D570-98, West Conshohocken, PA.
ASTM. (2011a). “Standard test method for lead in paint driers by EDTA Method.” ASTM D2374-05, West Conshohocken, PA.
ASTM. (2011b). “Standard test method for tensile properties of fiber reinforced polymer matrix composite bars.” ASTM D7205/D7205M-06, West Conshohocken, PA.
ASTM. (2012). “Standard test method for alkali resistance of fiber reinforced polymer (FRP) matrix composite bars used in concrete construction.” ASTM D7705/D7705M-12, West Conshohocken, PA.
ASTM. (2014a). “Standard test method for assignment of the glass transition temperatures by differential scanning calorimetry.” ASTM E1356-08, West Conshohocken, PA.
ASTM. (2014b). “Standard test method for compositional analysis by thermogravimetry.” ASTM E1131-08, West Conshohocken, PA.
ASTM. (2014c). “Standard test method for flexural properties of fiber reinforced pultruded plastic rods.” ASTM D4476/D4476M-14, West Conshohocken, PA.
ASTM. (2015). “Standard test methods for constituent content of composite materials.” ASTM D3171–15, West Conshohocken, PA.
ASTM. (2016). “Standard test method for apparent horizontal shear strength of pultruded reinforced plastic rods by the short-beam method.” ASTM D4475-02, West Conshohocken, PA.
Bakis, C. E. (1993). “FRP composites: Materials and manufacturing.” Fiber-reinforced-plastic for concrete structures: Properties and applications, A. Nanni, ed., Elsevier, Amsterdam, Netherlands, 13–58.
Bakis, C. E., Freimanis, A. J., Gremel, D., and Nanni, A. (1998). “Effect of resin material on bond and tensile properties of unconditioned and conditioned FRP reinforcement rods.” Proc., 1st Int. Conf. on Durability of Composites for Construction, B. Benmokrane and H. Rahman, eds., Sherbrooke, QC, Canada, 525–535.
Bank, L. C. (2006). Composites for construction: Structural design with FRP materials, Wiley, Hoboken, NJ.
Belarbi, A., and Wang, H. (2012). “Bond durability of FRP bars embedded in fiber-reinforced concrete.” J. Compos. Constr., 371–380.
Benmokrane, B., Elgabbas, F., Ahmed, E., and Cousin, P. (2015). “Characterization and comparative durability study of glass/vinylester, basalt/vinylester, and basalt/epoxy FRP bars.” J. Compos. Constr., 04015008.
Benmokrane, B., El-Salakawy, E., El-Ragaby, A., and Lackey, T. (2006). “Designing and testing of concrete bridge decks reinforced with glass FRP bars.” J. Bridge Eng., 217–229.
Benmokrane, B., and Rahman, H., eds. (1998). “Durability of fiber reinforced polymer (FRP) composites for construction.” Proc., First Int. Conf., Sherbrooke, QC, Canada, 692.
Benmokrane, B., Wang, P., Ton-That, T., Rahman, H., and Robert, J. F. (2002). “Durability of glass fiber-reinforced polymer reinforcing bars in concrete environment.” J. Compos. Constr., 143–153.
Carvelli, V., Fava, G., and Pisani, M. A. (2009). “Anchor system for tension testing of large diameter GFRP bars.” J. Compos. Constr., 344–349.
Castro, P. F., and Carino, N. J. (1998). “Tensile and nondestructive testing of FRP bars.” J. Compos. Constr., 17–27.
Chen, Y., Davalos, J. F., Ray, I., and Kim, H.-Y. (2007). “Accelerated aging tests for evaluations of durability performance of FRP reinforcing bars for concrete structures.” Compos. Struct., 78(1), 101–111.
Cinquin, J., and Medda, B. (2009). “Influence of laminate thickness on composite durability for long term utilisation at intermediate temperature (100–150°C).” Compos. Sci. Technol., 69(9), 1432–1436.
CSA (Canadian Standards Association). (2006). “Canadian highway bridge design code—Section 16, updated version for public review.” CAN/CSA-S6-14, Rexdale, ON, Canada.
CSA (Canadian Standards Association). (2010). “Specification for fibre-reinforced polymers.” CAN/CSA-S807, Rexdale, ON, Canada.
CSA (Canadian Standards Association). (2012). “Design and construction of building structures with fibre-reinforced polymers.” CAN/CSA-S806-12, Rexdale, ON, Canada.
Drouin, B., Latour, G., and Mohamed, H. (2011). “More than 10 years successful field applications of FRP bars in Canada.” CDCC 2011, The 4th Int. Conf. on Durability and Sustainability of Fiber Reinforced Polymer (FRP) Composites for Construction and Rehabilitation, Univ. of Sherbrooke, Sherrooke, QC, Canada, 6.
fib (International Federation for Structural Concrete). (2007). “FRP reinforcement in RC structures.”, Federal Institute of Technology, Lausanne, Switzerland.
Hollaway, L. C. (2008). “Advanced fibre polymer composite structural systems used in bridge engineering.” ICE manual of bridge engineering, Thomas Telford, London, 503–529.
Hollaway, L. C. (2010). “A review of the present and future utilisation of FRP composites in the civil infrastructure with reference to their important in-service properties.” Constr. Build. Mater., 24(12), 2419–2445.
Kamal, A., and Boulfiza, M. (2011). “Durability of GFRP rebars in simulated concrete solutions under accelerated aging conditions.” J. Compos. Constr., 473–481.
Kocaoz, S., Samaranayake, V. A., and Nanni, A. (2005). “Tensile characterization of glass FRP bars.” Compos. Part B, 36(2), 127–134.
Koller, R., Chang, S., and Xi, Y. (2007). “Fiber-reinforced bars under freeze-thaw cycles and different loading rates.” J. Compo. Mater., 41(1), 5–25.
Manalo, A. C., Benmokrane, B., Park, K., and Lutze, D. (2014). “Recent developments on FRP bars as internal reinforcement in concrete structures.” Concr. Aust., 40(2), 46–56.
Maranan, G. B., Manalo, A. C., Karunasena, W., Benmokrane, B., and Lutze, D. (2014). “Flexural behaviour of glass fibre reinforced polymer (GFRP) bars subjected to elevated temperature.” Proc., 23rd Australasian Conf. on the Mechanics of Structures and Materials (ACMSM23), Southern Cross Univ., East Lismore, NSW, Australia, 187–192.
Micelli, F., and Nanni, A. (2004). “Durability of FRP rods for concrete structures.” Constr. Build. Mater., 18(7), 491–503.
Mohamed, H. M., and Benmokrane, B. (2014). “Design and performance of reinforced concrete water chlorination tank totally reinforced with GFRP bars: Case study.” J. Compos. Constr., 05013001.
Mohamed, H. M., and Benmokrane, B. (2015). “Make the case: The use of FRP bars for soft-eyes in construction of tunnels.” Tunnels and tunneling: The official publication of the tunneling association of Canada, Tunnelling Association of Canada, Richmond, BC, Canada, 35–40.
MTO (Ministry of Transportation of Ontario). (2014). “Glass fibre reinfored polymer reinforcing bar.”, Toronto.
Nkurunziza, G., Debaiky, A., Cousin, P., and Benmokrane, B. (2005). “Durability of GFRP bars: A critical review of the literature.” Prog. Struct. Mater. Eng., 7(4), 194–209.
Park, C., Jang, C., Lee, S., and Won, J. (2008). “Microstructural investigation of long-term degradation mechanisms in GFRP dowel bars for jointed concrete pavement.” J. Appl. Polym. Sci., 108(5), 3128–3137.
Porter, M. L., Mehus, J., Young, K. A., O’Neil, E. F., and Barnes, B. A. (1997). “Aging for fiber reinforcement in concrete.” Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures, Vol. 2, Japan Concrete Institute, Tokyo, 59–66.
Portnov, G., and Bakis, C. E. (2008). “Analysis of stress concentration during tension of round pultruded composite rods.” Compos. Struct., 83(1), 100–109.
Pultrall. (2016). “Data sheet.” ⟨www.pultrall.com⟩ (Apr. 13, 2016).
Robert, M., and Benmokrane, B. (2013). “Combined effects of saline solution and moist concrete on long-term durability of GFRP reinforcing bars.” J. Constr. Build. Mater., 38, 274–284.
Robert, M., Cousin, P., and Benmokane, B. (2009). “Durability of GFRP reinforcing bars embedded in moist concrete.” J. Compos. Constr., 66–73.
Tannous, F. E., and Saadatmanesh, H. (1999). “Durability of AR glass fiber reinforced plastic bars.” Compos. Constr., 12–19.
Wisnom, M. R., and Jones, M. I. (1996). “Size effects in interlaminar tensile and shear strength of unidirectional glass fibre/epoxy.” J. Reinf. Plast. Compos., 15(1), 2–15.
Yi, S., and Hilton, H. H. (1998). “Effects of thermo-mechanical properties of composites on viscosity, temperature and degree of cure in thick thermosetting composite laminates during curing process.” J. Compos. Mater., 32(7), 600–622.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 21 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Sep 20, 2016
Accepted: Jan 27, 2017
Published online: May 27, 2017
Published in print: Oct 1, 2017
Discussion open until: Oct 27, 2017
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.