Exterior Concrete Beam-column Connection Reinforced with Glass Fiber Reinforced Polymers (GFRP) bars under Cyclic Loading

Document Type : Research Article


1 Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

2 Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.


This paper is devoted to assess the behavior of the exterior concrete beam-column connections reinforced with Glass Fiber Reinforced Polymers (GFRP) bars under cyclic loading. For this purpose, 8 different beam-column connections were experimentally investigated. In these specimens, concrete with compressive strength of 30 and 45 MPa was employed. In four of these connections, GFRP bars were used while the others were reinforced with steel bars. The confinement of longitudinal bars was different in the connections. The GFRP-reinforced beam-column connection showed an elastic behavior with very low plasticity features under cyclic loading. This resulted in lower energy dissipation compared to the steel-reinforced beam-column connections. The GFRP-reinforced beam-column connections showed lower stiffness than that of the steel-reinforced beam-column connections. Load-story drift envelope for specimens with GFRP bars showed an acceptable drift capacity. These specimens had the essential requirements for acting as a member of a moment frame in seismic regions. In case of GFRP strengthened specimens with low and high strength concrete, increasing the cyclic loading results in flexural failure of the beam in the beam-column connection region. Increasing the confinement of concrete beams leads to the reduction of crack width. Furthermore, at higher drifts, spalling was not observed in concrete surface in beam-column connection region. In the analytical parts of the study, specimens were simulated using the SeismoStruct software. Experimental and analytical results showed a satisfactory correlation.


Main Subjects

[1] R.L. Park, R. Park, T. Paulay, Reinforced concrete structures, John Wiley & Sons, 1975.
[2] T. Paulay, M.J.N. Priestley, Seismic design of reinforced concrete and masonry buildings, (1992).
[3] A.M. Said, Investigation of Reinforced Concrete Beam-column Joints Under Reversed Cyclic Loading, 2005.
[4] T.H.-K. Kang, S.-S. Ha, D.-U.J.A.S.J. Choi, Bar Pullout Tests and Seismic Tests of Small-Headed Bars in Beam-Column Joints, 107(1) (2010).
[5] S. Barbhuiya, A.M.J.E.S. Choudhury, A study on the size effect of RC beam–column connections under cyclic loading, 95 (2015) 1-7.
[6] M. Engindeniz, L.F. Kahn, Z.J.A.s.j. Abdul-Hamid, Repair and strengthening of reinforced concrete beam-column joints: State of the art, 102(2) (2005) 1.
[7] Y. Nakayama, H. Nakai, T. Kanakubo, BOND BEHABIOR BETWEEN DEFORMED ARAMID FIBER-REINFORCED PLASTIC REINFORCEMENT AND CONCRETE, in: The 14th World Conference on Earthquake Engineering October, 2008, pp. 12-17.
[8] A. Said, M.J.A.C.M. Nehdi, Use of FRP for RC frames in seismic zones: Part I. Evaluation of FRP beam-column joint rehabilitation techniques, 11(4) (2004) 205-226.
[9] H.A. Toutanji, M.J.A.s.j. Saafi, Flexural behavior of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars, 97(5) (2000) 712-719.
[10] S.R. Salib, G.J.S.J. Abdel-Sayed, Prediction of crack width for fiber-reinforced polymer-reinforced concrete beams, 101(4) (2004) 532-536.
[11] P. Vijay, Aging and design of concrete members reinforced with GFRP bars, (2000).
[12] P.X.J.J.o.c.f.c. Zou, Long-term deflection and cracking behavior of concrete beams prestressed with carbon fiber-reinforced polymer tendons, 7(3) (2003) 187-193.
[13] P.X.J.J.o.c.f.c. Zou, Flexural behavior and deformability of fiber reinforced polymer prestressed concrete beams, 7(4) (2003) 275-284.
[14] P.X.J.J.o.c.f.c. Zou, Theoretical study on short-term and long-term deflections of fiber reinforced polymer prestressed concrete beams, 7(4) (2003) 285-291.
[15] S. Alsayed, Y. Al-Salloum, T. Almusallam, M.J.S.P. Amjad, Concrete columns reinforced by glass fiber reinforced polymer rods, 188 (1999) 103-112.
[16] M. Grira, M. Saatcioglu, Reinforced concrete columns confined with steel or FRP grids, in: Proceedings of the 8th Canadian Conference on Earthquake Engineering, 1999, pp. 445-450.
[17] E.F. Shehata, Fibre-reinforced polymer (FRP) for shear reinforcement in concrete structures, (1999).
[18] T. Nagasaka, H. Fukuyama, M.J.S.p. Tanigaki, Shear performance of concrete beams reinforced with FRP stirrups, 138 (1993) 789-812.
[19] M. Sugita, NEFMAC-Grid type reinforcement, in: Fiber-Reinforced-Plastic (FRP) Reinforcement for Concrete Structures, Elsevier, 1993, pp. 355-385.
[20] E.A. Ahmed, F. Settecasi, B.J.J.o.B.E. Benmokrane, Construction and testing of GFRP steel hybrid-reinforced concrete bridge-deck slabs of sainte-catherine overpass bridges, 19(6) (2014) 04014011.
[21] B. Benmokrane, M. Eisa, S. El-Gamal, D. Thébeau, E.J.C.i. El-Salakawy, Pavement system suiting local conditions, 30(11) (2008) 34-39.
[22] H.M. Mohamed, B.J.J.o.C.f.C. Benmokrane, Design and performance of reinforced concrete water chlorination tank totally reinforced with GFRP bars: Case study, 18(1) (2013) 05013001.
[23] P.K. Dutta, D.M. Bailey, S.W. Tsai, D.W. Jensen, J.R. Hayes Jr, Composite Grids for Reinforcement of Concrete Structures, CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL, 1998.
[24] J. Lemaitre, R. Desmorat, Engineering damage mechanics: ductile, creep, fatigue and brittle failures, Springer Science & Business Media, 2005.
[25] W.J.S.P. Corley, Ductility of Column, Wall, and Beams--How Much is Enough?, 157 (1995) 331-350.
[26] J. Sabzi, M.R.J.C. Esfahani, B. Materials, Effects of tensile steel bars arrangement on concrete cover separation of RC beams strengthened by CFRP sheets, 162 (2018) 470-479.
[27] M.A. Aiello, L.J.J.o.C.f.C. Ombres, Structural performances of concrete beams with hybrid (fiber-reinforced polymer-steel) reinforcements, 6(2) (2002) 133-140.
[28] H.Y. Leung, R.J.S.S. Balendran, Flexural behaviour of concrete beams internally reinforced with GFRP rods and steel rebars, 21(4) (2003) 146-157.
[29] S.M. Alcocer, R. Carranza, D. Perez-Navarrete, R.J.P.j. Martinez, Seismic tests of beam-to-column connections in a precast concrete frame, 47(3) (2002) 70-89.
[30] E.Z. Beydokhty, H.J.L.A.j.o.s. Shariatmadar, structures, Behavior of damaged exterior RC beam-column joints strengthened by CFRP composites, 13(5) (2016) 880-896.
[31] A. Bossio, F. Fabbrocino, G.P. Lignola, A. Prota, G.J.B. Manfredi, Design Oriented Model for the Assessment of T-Shaped Beam-Column Joints in Reinforced Concrete Frames, 7(4) (2017) 118.
[32] J. Moehle, J. Hooper, C. Lubke, NEHRP Seismic Design Technical Brief No. 1-Seismic Design of Reinforced Concrete Special Moment Frames: A Guide for Practicing Engineers, 2008.
[33] A.C. Institute, Acceptance Criteria for Moment Frames Based on Structural Testing and Commentary (ACI 374.1-05), (2005).
[34] M.R. Ehsani, F.J.A.S.J. Alameddine, Design recommendations for type 2 high-strength reinforced concrete connections, 88(3) (1991) 277-291.
[35] M.N. Priestley, F. Seible, G.M. Calvi, G.M. Calvi, Seismic design and retrofit of bridges, John Wiley & Sons, 1996.
[36] H. Rezaee Azariani, M.R. Esfahani, H.J.S. Shariatmadar, C. Structures, Behavior of exterior concrete beam-column joints reinforced with Shape Memory Alloy (SMA) bars, 28 (2018).
[37] S. user Manual, Version 5.0. 1, Pavia, Italy. Seismo-Soft Inc. Supporting Services, (2010).
[38] J. Mander, M. Priestley, R.J.J.o.s.e. Park, Observed stress-strain behavior of confined concrete, 114(8) (1988) 1827-1849.
[39] F.C. Filippou, V.V. Bertero, E.P. Popov, Effects of bond deterioration on hysteretic behavior of reinforced concrete joints, (1983).
[40] A. Prota, F. De Cicco, E.J.J.o.E.E. Cosenza, Cyclic behavior of smooth steel reinforcing bars: experimental analysis and modeling issues, 13(4) (2009) 500-519.