Behavior Comparison of Uniaxial Cylindrical Columns Strengthened with CFRP

Document Type : Regular Paper

Authors

1 Assistant Professor, Department of Civil and Surveying Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran

2 M.Sc. Structural Eng., Department of Civil and Surveying Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran

Abstract

In recent years application of CFRP sheets in the strengthening of the concrete circular column has increased numerously. Knowing the exact behavior of concrete cylindrical columns confined with CFRP is of the first order of importance. ISIS Code of Canada has given relations for strength increase of circular columns confined with CFRP sheets, these relations are defined for a specified range of confinement pressure, and for higher confinement pressures there are no relations describing the behavior of the confined specimen. In this paper, cylindrical specimens with different concrete strengths and a variable number of CFRP layers were used. They were modeled in finite element software. After verification of models with laboratory works; results of finite element modeling were compared with ISIS Canada. The analytical results show that with a change in concrete strength the results have a different error from ISIS results. Therefore, for confinement pressure of more than the permissible value of ISIS code, change in the amount of strength increases was studied.

Keywords

Main Subjects


[1] Kwan, AKH., Chau, SL., Au, FTK. (2006). “Improving flexural ductility of high-strength concrete beams”. Proc ICE – Struct. Build, 159(6), pp. 339–347.
[2] Paultre, P., Legeron, F., Mongeau, D. (2001). “Influence of concrete strength and transverse reinforcement yield strength on behavior of high-strength concrete columns”. ACI Struct. J., 98(4): pp. 490–501.
[3] Cusson, D., Paultre, P. (1994). “High-strength concrete columns confined by rectangular ties”. J StructEng,120(3): pp. 783–804.
[4] Xiao, Y. (2004). “Applications of FRP composites in concrete columns”. Adv. Struct. Eng., Vol.7(4): pp. 335–343.
[5] Xiao, Y., Ma, R. (1997). “Seismic retrofit of RC circular columns using prefabricated composite jacketing”. J Struct. Eng., 123(10): pp. 1357–1364.
[6] Ilki, A., Peker, O., Karamuk, E., Demir, C., Kumbasar, N. (2008). “FRP retrofit of low and medium strength circular and rectangular reinforced concrete columns”. J Mater Civ. Eng., 20(2): pp. 169–88.
[7] Ozbakkaloglu, T. (2013). “Compressive behavior of concrete-filled FRP tube columns: assessment of critical column parameters”. Eng. Struct., 51: pp. 188–199.
[8] Xiao, Y., Wu, H. (2003). “Compressive behavior of concrete confined by various types of FRP composite jackets”. J Reinf Plast Compos, 22(13): pp. 1187–1201.
[9] Rousakis, TC., Karabinis, AI., Kiousis, PD. (2007). “FRP-confined concrete members: axial compression experiments and plasticity modelling”. Eng. Struct., 29(7): pp. 1343–1353.
[10] Ozbakkaloglu, T., Lim, JC., Vicent, T. (2013). “FRP-confined concrete in circular sections: review and assessment of stress–strain models”. Eng. Struct., 49: pp. 1068–1088.
[11] Idris, Y., Ozbakkaloglu, T. (2013). “Seismic behavior of high-strength concrete-filled FRP tube columns”. J. Compos. Constr., Vol. 17 (6) pp. 1943.
[12] Ozbakkaloglu, T. (2013). “Compressive behavior of concrete-filled FRP tube columns: assessment of critical column parameters”. Eng. Struct., Vol. 51 pp. 188–199.
[13] Li, Y., Fang, T., Chern, C. (2003). “A Constitutive Model for Concrete Cylinder Confined by Steel Reinforcement and Carbon Fiber Sheet”. pacific conference on earthquake engineering,.
[14] Li, Y., Lin, C., Sung, Y. (2003). “A constitutive model for concrete confined with carbon fiber reinforced plastics”. Mechanics of Materials, Vol. 35, pp 603–619.
[15] ISIS educational module 4. (2004). “An introduction to FRP strengthening of concrete structures”. prepared by ISIS Canada, February 2004.
[16] Majewski, S. (2003). “The mechanics of structural concrete in terms of elasto-plasticity”. SilesianPolytechnic Publishing House, Gliwice,.
[17] EN 1992-1-1. (2004). “ Eurocode 2 Design of concrete structures - Part 1-1: General rules and rules for buildings”.
[18] Wang, T., Hsu, T.T.C. (2001). “Nonlinear finite element analysis of concrete structures using newconstitutive models”. Computers and Structures, Vol. 79, Iss. 32, , pp. 2781–2791.
[19] Kmiecik, P., Kaminski, M. (2011). “Modelling of reinforced concrete structures and composite structures with concrete strength degradation taken into consideration”. Archives of civil and mechanical engineering, No. 3.
[20] Abaqus theory manual and users' manual, version 6.10. (2010).
[21] Bouchelaghem, H., Bezazi, A., Scarpa, F. (2011). “Compressive behavior of concrete cylindrical FRP-confined columns subjected to a new sequential loading technique”. Composites: Part B, Vol. 42, pp 1987–1993.
[22] Uya, B., Taoa, Z., Hanc, L. (2011). “Behaviour of short and slender concrete-filled stainless steel tubular columns”. Journal of Constructional Steel Research, Vol. 67, pp 360–378.