A research project was initiated to develop a nonferrous hybrid reinforcement system for concrete bridge decks by using continuous fiber-reinforced polymer (FRP) rebars and discrete randomly distributed polypropylene fibers. This hybrid system may eliminate problems related to the corrosion of steel reinforcement while providing requisite strength, stiffness, and desired ductility, which are shortcomings of FRP reinforcing system in plain concrete. This article presents the results of a part of this research program, i.e., the bond behaviors of this hybrid reinforcing system under monotonic and fatigue loading. Test results indicate that the addition of polypropylene fibers does not increase the ultimate bond strength, while providing enhanced ductile bond behavior. Fatigue loading can increase bond stiffness and bond capacity, while causing more brittle bond behavior. Polypropylene fibers can effectively decrease the bond degradation rate caused by fatigue loading.
Keesler, R.J. and Power, R.G. (1988). Corrosion of Epoxy Coated Rebars-Keys Segmental Bridge-Monroe County, Report No. 88-8A, FloridaDepartment of Transportation, Materials Office, Corrosion Research Laboratories , Gainesville, Fl.
2.
Rasheeduzzafar, A., Dakhil, F., Basa, M. and Khan, M. (1992). Performance of Corrosion-resisting Steels in Chloride-bearing Concrete, ACI Materials Journal , 89(5): 439-448.
3.
ACI Committee 544 (2002). State-of-the-Art Report on Fiber Reinforced Concrete. ACI 544.1R-96 (Reapproved 2002), p. 66, American Concrete Institute, Farmington Hills, Michigan.
4.
Ehsani, M.R. , Saadatmanesh, H. and Tao, S. (1997). Bond Behavior of Deformed GFRP Rebars, Journal of Composite Materials, 31(14): 1413-1430.
5.
Katz, A. ( 1999). Bond Mechanism of FRP Rebars to Concrete, Materials and Structures, 32(10): 761-768.
6.
Davalos, J.F. , Chen, Y. and Ray, I. (2008a). Effect of FRP Bar Degradation on Durability of Interface Bond with Concrete, Cement and Concrete Composites, 30(8): 722-730.
7.
Davalos, J.F., Chen, Y. and Ray, I. ( 2008b). Numerical Modeling of Interface Bond between Concrete and FRP Bar, In: Symposium of Advanced Materials, Structures and Mechanics - New Advances in the 21st Century at Earth & Space 2008 Conference - Science, Engineering, Construction and Operations in Challenging Environments, Long Beach, California, USA, 3-5 March.
8.
Cosenza, E., Manfredi, G. and Realfonzo, R. ( 1997). Behavior and Modeling of Bond of FRP Rebars to Concrete , Journal of Composites for Construction, 1(2): 40-51.
9.
Aiello, M.A. , Leone, M. and Pecce, M. (2007). Bond Performances of FRP Rebars-Reinforced Concrete, Journal of Materials in Civil Engineering, 19(3): 205-213.
10.
Achillides, Z. and Pilakoutas, K. (2004). Bond Behavior of Fiber Reinforced Polymer Bars under Direct, Journal of Composites for Construction, 8(2): 173-181.
11.
Nanni, A., Al-Zaharani, M.M., Al-Dulaijan, S.U., Bakis, C.E. and Boothby, T.E. ( 1995). Bond of FRP Reinforcement to Concrete - Experimental Results, In: Taerwe, L. (ed.), Proceedings of the Second International RILEM Symposium (FRPRCS-2), London, pp. 135-145.
12.
Malvar, L.J. , Cox, J.V. and Cochran, K.B. (2003). Bond Between Carbon Fiber Reinforced Polymer Bars and Concrete. 1: Experimental Study, Journal of Composites for Construction, 7(2): 154-163.
13.
Katz, A. ( 2000). Bond to Concrete of FRP Rebars after Cyclic Loading, Journal of Composites for Construction, 4(3): 137-144.
14.
Bakis, C.E., AL-Dulaijan, S.U., Nanni, A., Boothby, T.E. and Al-Zahrani, M.M. ( 1998). Effect of Cyclic Loading on Bond Behavior of GFRP Rods Embedded in Concrete Beams, Journal of Composites Technology & Research, 20(1): 29-37.
15.
Ezeldin, A. and Balaguru, P. ( 1989). Bond Behavior of Normal and High-strength Fiber Reinforced Concrete, ACI Materials Journal, 86(5): 515-524.
16.
Harajli, M.H. and Mabsout, M.E. (2002). Evaluation of Bond Strength of Steel Reinforcing Bars in Plain and Fiber-reinforced Concrete , ACI Structural Journal, 99(4): 509-517.
17.
ACI Committee 440 (2006). Guide for the Design and Construction of Concrete Reinforced with FRP Bars . ACI 440.1R-06, p. 44, American Concrete Institute, Farmington Hills, Michigan .
18.
Rilem 7-Ii-128 (1994). RC6: Bond Test for Reinforcing Steel. 1. Pull-out Test, In: RILEM Technical Recommendations for the Testing and Use of Construction Materials, pp. 102-105, E & FN Spon, UK.
19.
Losberg, A. ( 1963). Force Transfer and Stress Distribution at Anchorage and Curtailment of Reinforcement, Report No. 608, Chalmers University of Technology, Goteborg, Sweden.
20.
Aashto (2007). AASHTO LRFD Bridge Design Specifications, 4th edn, American Association of State Highway and Transportation Officials, Washington, DC.
21.
Demers, C.E. (1998). Tension-Tension Axial Fatigue of E-Glass Fiber-Reinforced Polymeric Composites: Fatigue Life Diagram, Construction and Building Materials, 12(1): 303-310.
22.
Mays, G.C. and Tilly, G.P. ( 1982). Long Endurance Fatigue Performance of Bonded Structural Joints, International Journal of Adhesion and Adhesives, 2(2): 109-113.
23.
Admi, M.R., Rahman, A.H. and Benmokrane, B. ( 2000). New Method for Testing Fiber-reinforced Polymer Rods under Fatigue, Journal of Composites for Construction, 4(4): 206-213.
24.
Demers, C.E. (1998). Fatigue Strength Degradation of E-Glass FRP Composites and Carbon FRP Composites, Construction and Building Materials, 12(5): 311-318.
25.
ACI Committee 318 (2005). Building Code Requirements for Structural Concrete (318-05) and Commentary (318R-05), p. 430, American Concrete Institute, Farmington Hills, Michigan .
26.
Choi, O.C. and Lee, W.S. ( 2002). Interfacial Bond Analysis of Deformed Bars to Concrete , ACI Structural Journal, 99(6): 750-756.
27.
Chaallal, O. and Benmokrane, B. (1993). Pullout and Bond Glass-Fiber Rods Embedded in Concrete and Cement Grout, Materials & Structures, 26(157): 167-175.
28.
Goto, Y. ( 1971). Cracks Formed in Concrete Around Deformed Tension Bars , Journal of the American Concrete Institute, 68(4): 244-251.
29.
Benmokrane, B., Tighiouart, B. and Chaallal, O. (1996). Bond Strength and Load Distribution of Composite GFRP Reinforcing Bars in Concrete, ACI Materials Journal, 93(3): 246-253.
30.
Tighiouart, B., Benmokrane, B. and Gao, D. (1998). Investigation of Bond in Concrete Member with Fiber Reinforced Polymer (FRP) Bars, Construction and Building Materials, 12(8): 453-462.
31.
ACI Committee 408 (2005). State-of-the-Art Report on Bond under Cyclic Loads. ACI 408.2R-92 (Reapproved 2005), p. 32, American Concrete Institute, Farmington Hills, Michigan .
32.
Gylltoft, K. , Cederwall, K., Elfgren, L. and Nilsson, L. (1982). Bond Failure in Reinforcement Concrete Under Monotonic and Cyclic Loading: A Fracture Mechanics Approach . Fatigue of Concrete Structures, SP-75, pp. 269-287, American Concrete Institute, Detroit.
33.
Rehm, G. and Eligehausen, R. ( 1979). Bond of Ribbed Bars under High Cycle Repeated Loads, ACI Journal, 76(2): 297-309.
34.
Clark, C.R. and Johnston, D.W. (1983). Early Loading Effects on Bond Strength, ACI Journal, 80(6): 532-539.
35.
Oh, B.H. and Kim, S.H. (2007). Realistic Models for Local Bond Stress-Slip of Reinforced Concrete under Repeated Loading, Journal of Structural Engineering, 133(2): 216-224.
