Advanced Steel Construction

Vol. 1, No. 2, pp. 17-28 (2005)



S. Fawzia1, X.L. Zhao1,*, R. Al-Mahaidi1 and S. Rizkalla2

1Department of Civil Engineering, Monash University, Clayton, Victoria 3800, Australia

2North Carolina State University, Raleigh, North Carolina, USA

(*Corresponding Author, Email: This email address is being protected from spambots. You need JavaScript enabled to view it.)




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This paper describes a series of double strap shear tests loaded in tension to investigate the bond betweenCFRP sheets and steel plates. Both normal modulus (240 GPa) and high modulus (640 GPa) CFRPs were used in the test program. Strain gauges were mounted to capture the strain distribution along the CFRP length. Different failure modes were observed for joints with normal modulus CFRP and those with high modulus CFRP. The strain distribution along the CFRP length was found to be similar for the two cases. A shorter effective bond length was obtained for joints with high modulus CFRP whereas larger ultimate load carrying capacity can be achieved for joints with normal modulus CFRP when the bond length is long enough. The Hart-Smith Model was modified to predict the effective bond length and ultimate load carrying capacity of joints between the normal modulus CFRP and steel plates. The Multilayer Distribution Model developed by the authors was modified to predict the load carrying capacity of joints between the high modulus CFRP and steel plates. The predicted values agreed well with experimental ones.



CFRP (Carbon Fibre Reinforced Polymer), Bond Failure, Double Strap Joints, Effective Bond Length,Steel Plate.


[1]     ISIS, “Reinforcing Concrete Structures with Fiber Reinforced Polymers (FRPs)”, Design Manual 3, ISIS Canada Design Manuals, ISIS, Manitoba, Canada, 2001.

[2]     Moy, S.S.J., “FRP Composites-Life Extension and Strengthening of Metallic Structures”, The Institute of Civil Engineers Design and Practice Guides, Institution of Civil Engineers (ICE). Thomas Telford Publishing, London, UK, 2001.

[3]     ACI Committee 440, “Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures”, Technical Committee Documents ACI 440.2R-02, ACI, USA, 2002.

[4]     Teng, J.G., Chen, J.F., Smith, S.T. and Lam, L., “FRP Strengthened RC Structures”. John Wiley & Sons Ltd, West Sussex, UK, 2002.

[5]     Oehler, D.J. and Seracino, R., “Design of FRP and Steel Plated RC Structures: Retrofitting beams and slabs for strength, stiffness and ductility”, Elsevier, Oxford, UK, 2004.

[6]     Fawzia, S., Al-Mahaidi, R., Zhao, X.L. and Rizkalla, S., “Comparative Study of Failure Mechanisms in Steel and Concrete Members Strengthened with CFRP Composites, in Developments in Mechanics of Structures and Materials”, Deeks, A.J. and Hao, H. (eds), Balkema Publishers, London, 2004, pp.71-76.

[7]     Hart-Smith, L.J., “Design and Analysis of Adhesive-Bonded Joints”, Air Force Conference on Fibrous Composites in Flight Vehicle Design, September, Douglas Paper 6059, Dayton, Ohio, USA, 1972.

[8]     Hart-Smith, L.J., “Adhesive-Bonded Double-Lap Joints”, Technical Report NASA CR-112235, Douglas Aircraft Company, Long Beach, California, USA, 1973.

[9]     Fawzia, S., Zhao, X.L., Al-Mahaidi, R. and Rizkalla, S., “Investigation Into the Bond between CFRP and Steel Tubes”, The Second International Conference on FRP Composites in Civil Engineering, December, Adelaide, 2004, pp.733-739.

[10]   Jiao, H. and Zhao, X.L., CFRP Strengthened Butt-Welded Very High Strength (VHS) Circular Steel Tubes, Thin-Walled Structures, 2004, 42(7), pp.963-978.

[11]   Hart-Smith, L.J., “Bolted and Bonded Joints”, Composites, Vol. 21, ASM Handbook, American Society for Materials (ASM) International, USA, 2001.

[12]   Matta, F., “Bond Between Steel and CFRP Laminates for Rehabilitation of Metallic Bridges”, PhD Thesis, Faculty of Engineering, University of Padua, Italy, 2003.

[13]   Liu, H.B., Zhao, X.L., Al-Mahaidi, R. and Rizkalla, S., “Analytical Bond Models Between Steel and Normal Modulus CFRP”, 4th International Conference on Advances in Steel Structures, Shanghai, June 2005.