Nonlinear 2D Finite-Element Modeling of RC Beams Strengthened with Prestressed NSM CFRP Reinforcement
Publication: Journal of Composites for Construction
Volume 20, Issue 4
Abstract
This paper presents a comprehensive two-dimensional (2D) nonlinear finite-element (FE) analysis of reinforced concrete (RC) beams strengthened with prestressed or non-prestressed near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) reinforcement. In this model, the bond-slip relationship between the steel reinforcement and surrounding concrete as well as that between the NSM CFRP reinforcement and concrete substrate are precisely modeled with cohesive interface elements. Based on the smeared crack approach, the tensile and shear behavior for concrete cracking are considered using appropriate models. The prestressing effect was enforced in the NSM CFRP reinforcement using the equivalent temperature method, and the anchoring effect of U-shaped steel end anchors on the NSM CFRP reinforcement is properly implemented in the model. Moreover, the radial stresses induced by the tensile steel bars on the surrounding concrete are properly considered, and the bar-end concrete cover separation failure mode is successfully captured. Comparisons between the numerical and experimental results confirm that the proposed FE method is appropriate for predicting the load-deflection curves, failure modes, and cracking patterns of the strengthened beams. Based on this study, the 2D FE model is utilized to conduct a parametric study and can be used to aid in realistic structural applications and optimization of the use of prestressed/non-prestressed NSM reinforcement for strengthening RC beams.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to acknowledge financial support from the National Basic Research Program of China (973 Program) (No. 2012CB026200), the Natural Science Foundation of Jiangsu Province, China (No. BK2012023), the National High Technology Research and Development Program of China (No. 2012AA03A204), and the International Science and Technology Cooperation of Program of China (No. 2012DFG20510). The authors also wish to thank Tian-Sheng Shi in Hong Kong University of Science and Technology for his help in acquiring MSC.MARC software.
References
ACI (American Concrete Institute). (2004). “Prestressing concrete structures with FRP tendons.” ACI 440.4R-04, Farmington Hills, MI.
ACI (American Concrete Institute). (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.” ACI 440.2R-08, Farmington Hills, MI.
Ansourian, P. (1981). “Experiments on continuous composite beams.” Proc. Inst. Civ. Eng., 71(2), 25–51.
Badawi, M., and Soudki, K. (2009). “Flexural strengthening of RC beams with prestressed NSM CFRP rods-experimental and analytical investigation.” Constr. Build. Mater., 23(10), 3292–3300.
Barros, J. A., Dias, S. J., and Lima, J. L. (2007). “Efficacy of CFRP-based techniques for the flexural and shear strengthening of concrete beams.” Cem. Concr. Compos., 29(3), 203–217.
Barros, J. A., and Fortes, A. S. (2005). “Flexural strengthening of concrete beams with CFRP laminates bonded into slits.” Cem. Concr. Compos., 27(4), 471–480.
Bažant, Z. P., and Oh, B. H. (1983). “Crack band theory for fracture of concrete.” Matériaux et Constr., 16(3), 155–177.
Buyukkaragoz, A., Kalkan, I., and Lee, J. H. (2013). “A numerical study of the flexural behavior of concrete beams reinforced with AFRP bars.” Strength. Mater., 45(6), 716–729.
Buyukozturk, O. (1977). “Nonlinear analysis of reinforced concrete structures.” Comput. Struct., 7(1), 149–156.
Camata, G., Spacone, E., and Zarnic, R. (2007). “Experimental and nonlinear finite element studies of RC beams strengthened with FRP plates.” Compos. B Eng., 38(2), 277–288.
CEB-FIP. (1993). “Model code 90.” Lausanne, Switzerland.
Chansawat, K. (2003). “Nonlinear finite element analysis of reinforced concrete structures strengthened with FRP laminates.” Ph.D. thesis, Oregon State Univ., Corvallis, OR.
De Lorenzis, L. (2004). “Anchorage length of near-surface mounted fiber-reinforced polymer bars for concrete strengthening-analytical modeling.” ACI Struct. J., 101(3), 375–386.
De Lorenzis, L., and Nanni, A. (2002). “Bond between near-surface mounted fiber-reinforced polymer rods and concrete in structural strengthening.” ACI Struct. J., 99(2), 123–132.
De Lorenzis, L., Rizzo, A., and La Tegola, A. (2002). “A Modified pull-out test for bond of near-surface mounted FRP rods in concrete.” Compos. B Eng., 33(8), 589–603.
De Lorenzis, L., and Teng, J. G. (2007). “Near-surface mounted FRP reinforcement: An emerging technique for strengthening structures.” Compos. B Eng., 38(2), 119–143.
Gao, B., Leung, C. K., and Kim, J. K. (2005). “Prediction of concrete cover separation failure for RC beams strengthened with CFRP strips.” Eng. Struct., 27(2), 177–189.
Hassan, T. K., and Rizkalla, S. H. (2004). “Bond mechanism of near-surface-mounted fiber-reinforced polymer bars for flexural strengthening of concrete structures.” ACI Struct. J., 101(6), 830–839.
Hawileh, R. A. (2012). “Nonlinear finite element modeling of RC beams strengthened with NSM FRP rods.” Constr. Build. Mater., 27(1), 461–471.
Hawileh, R. A. (2015). “Finite element modeling of reinforced concrete beams with a hybrid combination of steel and aramid reinforcement.” Mater. Design., 65, 831–839.
Hognestad, E., Hanson, N. W., and McHenry, D. (1955). “Concrete stress distribution in ultimate strength design.” ACI J. Proc., 52(12), 455–479.
Johnson, R. P. (1975). Composite structures of steel and concrete, Granada Ltd., London.
Kachlakev, D., Miller, T., Yim, S., Chansawat, K., and Potisuk, T. (2001). “Finite element modeling of concrete structures strengthened with FRP laminates.”, United States Dept. of Transportation Federal Highway Administration and the Oregon Dept. of Transportation, Salem, OR.
Kishi, N., Zhang, G., and Mikami, H. (2005). “Numerical cracking and debonding analysis of RC beams reinforced with FRP sheet.” J. Compos. Constr., 507–514.
Lin, X., and Zhang, Y. X. (2013). “Novel composite beam element with bond-slip for nonlinear finite-element analyses of steel/FRP-reinforced concrete beams.” J. Struct. Eng., 06013003.
Lin, X., and Zhang, Y. X. (2014). “Evaluation of bond stress-slip models for FRP reinforcing bars in concrete.” Compos. Struct., 107, 131–141.
MSC.MARC [Computer software]. MSC Software, Santa Ana, CA.
Nie, J., and Cai, C. (2003). “Steel-concrete composite beams considering shear slip effects.” J. Struct. Eng., 495–506.
Nordin, H., and Täljsten, B. (2006). “Concrete beams strengthened with prestressed near surface mounted CFRP.” J. Compos. Constr., 60–68.
Nour, A., Massicotte, B., Yildiz, E., and Koval, V. (2007). “Finite element modeling of concrete structures reinforced with internal and external fibre-reinforced polymers.” Can. J. Civ. Eng., 34(3), 340–354.
Okamura, H., and Maekawa, K. (1991). “Nonlinear analysis and constitutive models of reinforced concrete.” Giho-do Press, Univ. of Tokyo, Tokyo.
Omran, H. Y., and El-Hacha, R. (2012). “Nonlinear 3D finite element modeling of RC beams strengthened with prestressed NSM-CFRP strips.” Constr. Build. Mater., 31, 74–85.
Petersson, P. E. (1981). “Crack growth and development of fracture zone in plain concrete and similar materials.”, Division of Building Materials, Lund Institute of Technology, Lund, Sweden.
Rafi, M. M., and Nadjai, A. (2012). “Comparison of numerical behaviors of FRP reinforced concrete beams using three smeared crack models.” Mater. Struct., 45(1–2), 93–106.
Rezazadeh, M., Costa, I., and Barros, J. (2014). “Influence of prestress level on NSM CFRP laminates for the flexural strengthening of RC beams.” Compos. Struct., 116, 489–500.
Rots, J. G. (1988). “Computational modelling of concrete fracture.” Ph.D. thesis, Delft Univ. of Technology, Delft, Netherlands.
Sharaky, I. A., Torres, L., Comas, J., and Barris, C. (2014). “Flexural response of reinforced concrete (RC) beams strengthened with near surface mounted (NSM) fibre reinforced polymer (FRP) bars.” Compos. Struct., 109, 8–22.
Soliman, S. M., El-Salakawy, E., and Benmokrane, B. (2010). “Flexural behaviour of concrete beams strengthened with near surface mounted fibre reinforced polymer bars.” Can. J. Civ. Eng., 37(10), 1371–1382.
Supaviriyakit, T., Pornpongsaroj, P., and Pimanmas, A. (2004). “Finite element analysis of FRP-strengthened RC beams.” Songklanakarin J. Sci. Technol., 26(4), 497–507.
Teng, J. G., De Lorenzis, L., Wang, B., Li, R., Wong, T. N., and Lam, L. (2006). “Debonding failures of RC beams strengthened with near surface mounted CFRP strips.” J. Compos. Constr., 92–105.
Teng, J. G., Smith, S. T., Yao, J., and Chen, J. F. (2003). “Intermediate crack-induced debonding in RC beams and slabs.” Constr. Build. Mater., 17(6), 447–462.
Tepfers, R. (1973). “A theory of bond applied to overlapped tensile reinforcement splices for deformed bars.” Division of Concrete Structures, Chalmers Univ. of Technology, Göteborg, Sweden.
Wu, G., Dong, Z. Q., Wu, Z. S., and Zhang, L. W. (2013). “Performance and parametric analysis of flexural strengthening for RC beams with NSM-CFRP bars.” J. Compos. Constr., 04013051.
Yang, Z. J., Chen, J. F., and Proverbs, D. (2003). “Finite element modelling of concrete cover separation failure in FRP plated RC beams.” Constr. Build. Mater., 17(1), 3–13.
Zhang, S. S. (2012). “Behaviour and modelling of RC beams strengthened in flexure with near-surface mounted FRP strips.” Ph.D. thesis, Hong Kong Polytechnic Univ., Hong Hom, Hong Kong.
Zhang, S. S., and Teng, J. G. (2014). “Finite element analysis of end cover separation in RC beams strengthened in flexure with FRP.” Eng. Struct., 75, 550–560.
Zhang, S. S., Teng, J. G., and Yu, T. (2013). “Bond-slip model for CFRP strips near-surface mounted to concrete.” Eng. Struct., 56, 945–953.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 20 • Issue 4 • August 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Feb 22, 2015
Accepted: Oct 22, 2015
Published online: Jan 13, 2016
Discussion open until: Jun 13, 2016
Published in print: Aug 1, 2016
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.