Evaluation of Physical and Durability Characteristics of New Headed Glass Fiber–Reinforced Polymer Bars for Concrete Structures
Publication: Journal of Composites for Construction
Volume 21, Issue 2
Abstract
This paper presents the results of a collaborative research project between Quebec’s Ministry of Transportation and Ontario’s Ministry of Transportation, which aimed at characterizing a new type of headed glass fiber–reinforced polymer (GFRP) reinforcing bar and evaluating its suitability as internal reinforcement for concrete structures. To achieve these objectives, the project was implemented in three stages: (1) evaluation of the physical and mechanical properties; (2) determination of the pullout behavior in concrete; and (3) characterization of the long-term durability of the headed GFRP bars. A total of 57 specimens embedded in a 200-mm concrete cube were tested with the direct pullout test to investigate the effect of confinement, bar size, concrete compressive strength, and exposure conditions on the pullout behavior of the headed GFRP bars. Simultaneously, microstructural analyses and measurements of the physicochemical and mechanical properties were carried out on conditioned and unconditioned headed GFRP bars. The results show that the materials, geometry, and interface configuration of the head provided very good mechanical interlocking to the GFRP bars. Up to 63 and 53% of the guaranteed tensile strength of the straight GFRP bars were achieved for 15.9- and 19-mm diameter bars with headed ends, respectively. Scanning electron microscopy and differential scanning calorimetry showed no material changes in the head and bars after exposure to alkaline solution and freeze–thaw cycling. Exposure to the alkaline solution under sustained loading had the most detrimental effect, with the bar retaining 79.4% of its pullout strength. The results indicate that the tested headed GFRP bar has suitable mechanical and durability properties for use as reinforcement in concrete bridge components.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors wish to express their gratitude and sincere appreciation to the Natural Sciences and Engineering Research Council of Canada (NSERC), the NSERC Research Chair in Innovative FRP Reinforcement for Concrete Structures, the Fonds de recherche du Québec en nature et technologies (FRQ-NT), and the Ministry of Transport Quebec for financing this research work. The material support from Pultrall Inc. (Thetford Mines, Quebec, Canada) and 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 gratefully acknowledged. The third author is quite appreciative of the scholarship granted by the Australian Government Endeavour Research Fellowships, enabling him to undertake his research and professional development at the University of Sherbrooke.
References
ACI (American Concrete Institute). (2008). “Metric specification for carbon & 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., and Benmokrane, B. (2009). “Pullout capacity of GFRP bars.”, Univ. of Sherbrooke, Sherbrooke, QC.
Ahmed, E., El-Sayed, A. K., El-Salakawy, E. F., and Benmokrane, B. (2010). “Bend strength of FRP stirrups: Comparison and evaluation of testing methods.” J. Compos. Constr., 3–10.
Al-Dulaijian, S., Al-Zahrani, M., Nanni, A., and Boothby, T. E. (2001). “Effect of environmental pre-conditioning on bond of FRP reinforcement to concrete.” J. Reinf. Plast. Compos., 20(10), 882–890.
Alves, J., El-Ragaby, A., and El-Salakawy, E. (2011). “Durability of GFRP bars’ bond to concrete under different loading and environmental conditions.” J. Compos. Constr., 249–262.
ASTM. (2010). “Standard test method for water absorption of plastics.” ASTM D570, West Conshohocken, PA.
ASTM. (2011). “Standard test method for tensile properties of fiber reinforced polymer matrix composite bars.” ASTM D7205/D7205M–11, West Conshohocken, PA.
ASTM. (2011). “Standard test methods for constituent content of composite materials.” ASTM D3171, West Conshohocken, PA.
ASTM. (2012). “Standard test methods for linear thermal expansion of solids materials by thermo-mechanical analysis.” ASTM E831, West Conshohocken, PA.
ASTM. (2014). “Standard test method for compositional analysis by thermogravimetry.” ASTM E1131, West Conshohocken, PA.
ASTM. (2015). “Standard classification system and basis for specification for polyphthalamide (PPA) injection molding materials.” ASTM D5336, West Conshohocken, PA.
ASTM. (2015a). “Standard test method for transition temperatures and enthalpies of fusion and crystallization of polymers by differential scanning calorimetry.” ASTM D3418-15, West Conshohocken, PA.
ASTM. (2015b). “Standard test method for resistance of concrete to rapid freezing and thawing.” ASTM C666-a5, West Conshohocken, PA.
Azimi, H., Sennah, K., Tropynina, E., Goremykin, S., Lucic, S., and Lam, M. (2014). “Anchorage capacity of concrete bridge barriers reinforced with GFRP bars with headed ends.” J. Bridge Eng., .
Bank, L. C., Puterman, M., and Katz, A. (1998). “The effect of material degradation on bond properties of fiber reinforced plastic reinforcing bars in concrete.” ACI Mater. J., 95(3), 232–243.
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., Tighiouart, B., and Chaallal, O. (1996). “Bond strength and load distribution of composite GFRP reinforcing bars in concrete.” ACI Mater. J., 93(3), 246–253.
Benmokrane, B., Wang, P., Ton-That, T., Rahman, H., and Robert, J. F. (2002). “Durability of glass fiber reinforcing bars in concrete environment.” J. Compos. Constr., 143–153.
Cosenza, E., Manfredi, G., and Realfonzo, R. (1997). “Behavior and modeling of bond of FRP rebars to concrete.” J. Compos. Constr., 40–51.
CSA (Canadian Standards Association). (2012). “Design and construction of building structures with fibre-reinforced polymers.” CSA S806-12, Rexdale, ON, Canada.
CSA (Canadian Standards Association). (2014). “Canadian highway bridge design code—Section 16, updated version for public review.” CSA S6-14, Rexdale, ON, Canada.
CSA (Canadian Standards Association). (2015). “Specification for fibre-reinforced polymers.” CSA S807, Rexdale, ON, Canada.
Davalos, J. F., Chen, Y., and Ray, I. (2008). “Effect of FRP bar degradation on interface bond with high strength concrete.” Cem. Concr. Compos., 30(8), 722–730.
El-Salakawy, E. F., Benmokrane, B., and Brière, F. (2005). “Glass FRP composite bars for concrete bridge barriers.” J. Sci. Eng. Compos. Mater., 12(3), 167–192.
Harajli, M., and Abouniaj, M. (2010). “Bond performance of GFRP bars in tension: Experimental evaluation and assessment of ACI 440 guidelines.” J. Compos. Constr., 659–668.
Homam, S. M., and Sheikh, S. A. (2000). “Durability of fibre reinforced polymers used in concrete structures.” Proc., 3rd Int. Conf. on Advanced Materials in Bridges and Structures, Ottawa, Canada, 751–758.
Islam, S., Afefy, H. A., Sennah, K., and Azimi, H. (2015). “Bond characteristics of straight- and headed-end, ribbed-surface, GFRP bars embedded in high-strength concrete.” Constr. Build. Mater., 83, 283–298.
Koller, R., Chang, S., and Xi, Y. (2007). “Fiber-reinforced bars under freeze-thaw cycles and different loading rates.” J. Compos. 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. Australia, 40(2), 46–56.
Mashima, M., and Iwamoto, K. (1993). “Bond characteristics of FRP rod and concrete after freezing and thawing deterioration.” Proc., Int. Symp. on Fiber-Reinforced-Plastic Reinforcement for Concrete Structures, A. Nanni and C. W. Dolan, eds., 51–69.
Micelli, F., and Nanni, A. (2004). “Durability of FRP rods for concrete structures.” Constr. Build. Mater., 18(7), 491–503.
Okelo, R., and Yuan, R. L. (2005). “Bond strength of fibre reinforced polymer rebars in normal strength concrete.” J. Compos. Constr., 203–213.
Ozbolt, J., Eligehausen, R., Periskic, G., and Mayer, U. (2007). “3D FE analysis of anchor bolts with large embedment depths.” Eng. Fract. Mech., 74(1–2), 168–178.
Platt, D. (2003). “Engineering and high performance plastics.”, Rapra Technology, Shropshire, U.K.
Reza Esfahani, M., Rakhshanimehr, M., and Roohollah Mousavi, S. (2013). “Bond strength of lap-spliced GFRP bars in concrete beams.” J. Compos. Constr., 314–323.
Robert, M., and Benmokrane, B. (2010). “Effect of aging on bond of GFRP bars embedded in concrete.” Cem. Concr. Compos., 32(6), 461–467.
Shahidi, F., Wegner, L. D., and Sparling, B. F. (2006). “Investigation of bond between fibre-reinforced polymer bars and concrete under sustained loads.” Can. J. Civ. Eng., 33(11), 1426–1437.
Sheikh, S. A. (2007). “Effect of freeze-thaw climatic conditions on long-term durability of FRP strengthening systems.” Univ. of Toronto, Toronto.
Thomson, M. K., Jirsa, J. O., Breen, J. E., and Klinger, R. E. (2002). “Anchorage behavior of headed reinforcement: Literature review.” Univ. of Texas at Austin, Austin, TX.
Tighiouart, B., Benmokrane, B., and Gao, D. (1998). “Investigation of bond in concrete member with fibre reinforced polymer (FRP) bars.” Constr. Build. Mater., 12(8), 453–462.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 21 • Issue 2 • April 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: Feb 23, 2016
Accepted: Jun 13, 2016
Published online: Aug 11, 2016
Discussion open until: Jan 11, 2017
Published in print: Apr 1, 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.