This is an open access article distributed under the CC BY-NC-ND 4.0 terms and conditions.
Volume 16 article 550 pages: 430 - 440
Confinement of both existing and newly constructed reinforced concrete (RC) frames by fibre reinforced polymer (FRP) has been commonly used in recent decades. This is because of its ability to enhance the behavior of RC frames under lateral loading.The purpose of this research is to perform a numerical study on effect of FRP confinement on strength and ductility of RC frames using OpenSEES software.After evaluating the accuracy of numerical model results by comparison with experimental results, the behavior of FRP-resistant frames is discussed.The 8-story studied building is reinforced in various ways by GFRP and CFRP composite sheets.Results of nonlinear analysis show that un-wrapped frame exhibits low resistance and less energy absorption.However, the loading capacity and the performance level have improved significantly in the frames strengthened with FRP materials.Also, increased capacity and reduced drift present more amount of increment in cases which CFRP materials are used.
The authors would like to thank M. Alborzi for valuable comments on the numerical analyses and great help during this research.Discussions with M. Forughi are also appreciated.
FEMA-547. Techniques for the Seismic Rehabilitation of Existing Buildings. Federal Emergency Management Agency (FEMA), USA, 2006.
Xiao, Y., Wu, H. Compressive behavior of concrete confined by carbon fiber composite jackets. Journal of materials in civil engineering, 12 (2): 139-146, 2000.
Karbhari, V.M., Gao, Y. Composite jacketed concrete under uniaxial compression-verification of simple design equations. Journal of materials in civil engineering, 9 (4): 185-193, 1997.
Harajli, M.H., Hantouche, E. and Soudki, K. Stress-strain model for fiber-reinforced polymer jacketed concrete columns. ACI structural journal, 103 (5): 672, 2006.
Wu, G., Lu, Z., Wu, Z. Stress–strain relationship for FRP-confined concrete cylinders. In Proceedings of the 6th international symposium on FRP reinforcement for concrete structures (FRPRCS), Singapore 552-60, 2003.
Wei, Y.Y., Wu, Y.F. Unified stress–strain model of concrete for FRP-confined columns. Construction and Building Materials, 26(1): 381-392, 2012.
Saadatmanesh, H., Ehsani, M. R., Jin, L. M. Seismic Strengthening of Circular Bridge Pier Models with Fiber Composites. ACI Structural Journal, 93(6): 936- 947, 1996.
Chaallal, O., Shahawy, M., Hassan, M. Performance of axially loaded short rectangular columns strengthened with carbon fiber-reinforced polymer wrapping. Journal of Composites for Construction, 7(3): 200- 208, 2003.
Balsamo, A., Colombo, A., Manfredi, G., Negro, P., Prota, A. Seismic behavior of a full-scale RC frame repaired using CFRP laminates. Engineering Structures, 27(5): 769–780, 2005.
De Luca, A., Nardone, F., Matta, F., Nanni, A., Lignola, G.P., Prota, A. Structural evaluation of full-scale FRP-confined reinforced concrete columns. Journal of Composites for Construction, 15(1): 112–123, 2011.
Wang, Z. Y., Wang, D.Y., Sheikh, S.A., Liu, J.T. Seismic performance of FRP-confined circular RC columns. International Conference on FRP Composites in Civil Engineering, Beijing, China, 2010.
Ronagh, H.R., Eslami, A. Flexural retrofitting of RC buildings using GFRP/CFRP–A comparative study. Composites: Part B, 46: 188-196, 2013.
OpenSees. Open system for earthquake engineering simulation. Pacific Earthquake Engineering Research Center, University of California, Berkeley, USA, 2016.
Mander, J. B., Priestley, M. J. N. Theoretical stress-strain model for confined concrete. Journal of Structural Engineering, 114(8): 1804-1826, 1988.
Lam, L., Teng, J.G. Design-oriented stress–strain model for FRP-confined concrete. Journal of Construction and Building Materials, 17 (6): 471-489, 2003.
ACI Committee. Building code requirements for structural concrete (ACI 318-02) and commentary. American Concrete Institute, International Organization for Standardization, 2002.
BHRC. Iranian code of practice for seismic resistant design of buildings (Standard No. 2800). Building and Housing Research Center, Tehran, Iran, 2014.
Mahini, S.S, Ronagh, H.R. Web-bonded FRPs for relocation of plastic hinges away from the column face in exterior RC joints. Composite Structures, 93(10): 2460–2472, 2011.
Mostofinejad, D., Mahmoudabadi, E. Grooving as alternative method of surface preparation to postpone debonding of FRP laminates in concrete beams. Journal of Composites for Construction, 14(6): 804– 811, 2010.
Kent, D.C., Park, R. Flexural members with confined concrete. Journal of the Structural Division, 97 (7): 1969-1990, 1971.
Di Ludovico M, Prota A, Manfredi G, Cosenza E. Seismic strengthening of an under-designed RC structure with FRP. Earthquake Engineering Structural Dynamics, 37:141–62, 2008.
Inel M, Ozmen HB. Effects of plastic hinge properties in nonlinear analysis of reinforced concrete buildings. Engineering Structures, 28: 1494–502, 2006.
Tahghighi H. Earthquake fault induced surface rupture–A hybrid strong ground motion simulation technique and discussion for structural design. Earthquake Engineering and Structural Dynamics 40: 1591-1608, 2011.
TahghighiH. Simulation of strong ground motion using the stochastic method: Application and validation for near-fault region. Journal of Earthquake Engineering 16: 1230-1247, 2012.
Mortezaei, A., Ronagh, H.R., Kheyroddin A. Seismic evaluation of FRP strengthened RC buildings subjected to near-fault ground motions having fling step. Composite Structures 92: 1200–1211, 2010.