Material Laws of FRP-Strengthened RC Element in Biaxial Tension–Compression
Publication: Journal of Composites for Construction
Volume 21, Issue 5
Abstract
The truss model approach is widely used to predict the behavior of fiber-reinforced polymer (FRP)-strengthened reinforced concrete (RC) elements in shear. The constitutive laws of each material components, namely concrete, steel, and FRP reinforcement, are essential in the truss model theory. This paper, which is one of a series of papers emphasizing on constitutive modeling of FRP-strengthened RC in shear, focuses on experimental and analytical investigations of constitutive laws of FRP-strengthened RC under biaxial tension–compression loading. The effect of two key parameters, specifically the softening coefficient and the Hsu-Zhu ratios, were carefully investigated by testing six full-scale panels. The results indicated that the softening coefficient and the Hsu-Zhu ratios for FRP-strengthened RC vary greatly compared to RC elements without FRP reinforcement and are heavily affected by parameters such as FRP stiffness and principal tensile strains. Furthermore, analytical expressions were proposed for the softening coefficient and the Hsu-Zhu ratios based on the experimental results.
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Acknowledgments
This research was supported by the National Science Foundation (NSF), award number 1100930. Steel reinforcements and FRP materials were a donation from Gerdau Ameristeel Co. and FYFE. Co, respectively. Their support is greatly acknowledged.
References
ASTM. (2014). “Standard test method for tensile properties of polymer matrix composite materials.” ASTM D3039/D3039M-14, West Conshohocken, PA.
Belarbi, A., Bae, S. W., Ayoub, A., Kuchma, D., Mirmiran, A., and Okeil, A. (2011). “Design of FRP systems for strengthening concrete girders in shear.”, Transportation Research Board, Washington, DC.
Belarbi, A., and Hsu, T. T. C. (1995). “Constitutive laws of softened concrete in biaxial tension compression.” ACI Struct. J., 92(5), 562–573.
Bousselham, A., and Chaallal, O. (2008). “Mechanisms of shear resistance of concrete beams strengthened in shear with externally bonded FRP.” J. Compos. Constr., 499–512.
Chen, G. M., Teng, J. G., Chen, J. F., and Rosenboom, O. A. (2010). “Interaction between steel stirrups and shear-strengthening FRP strips in RC beams.” J. Compos. Constr., 498–509.
Hsu, T. T. C., and Zhu, R. R. H. (2002). “Softened membrane model for reinforced concrete elements in shear.” ACI Struct. J., 99(4), 460–469.
Izumo, J., Shin, H., Maekawa, K., and Okamura, H. (1991). “An analytical model for RC panels subjected to in-plane stresses.” Proc., Int. Workshop on Concrete Shear in Earthquake, London.
Lee, G. Y., and Kim, W. (2009). “Cracking and tension stiffening behavior of high strength concrete tension members subjected to axial load.” Adv. Struct. Eng., 12(2), 127–137.
Moslehy, Y. (2010). “Constitutive relationships and smart aggregates-based damage evaluation of FRP retrofitted concrete membrane elements.” Ph.D. thesis, Univ. of Houston, Houston.
Vecchio, F. J., and Collins, M. P. (1981). “Stress-strain characteristic of reinforced concrete in pure shear.”, International Association of Bridge and Structural Engineering, Zurich, Switzerland, 221–225.
Yang, G., Zomorodian, M., Belarbi, A., and Ayoub, A. (2015). “Uniaxial tensile stress-strain relationships of RC elements strengthened with FRP sheets.” J. Compos. Constr., .
Zhu, R. R. H., and Hsu, T. T. C. (2002). “Poisson effect in reinforced concrete membrane elements.” ACI Struct. J., 99(5), 631–640.
Zomorodian, M., Yang, G., Belarbi, A., and Ayoub, A. S. (2016). “Cracking behavior and crack width predictions of FRP strengthened RC members under tension.” Eng. Struct., 125, 313–324.
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Published In
Journal of Composites for Construction
Volume 21 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Aug 11, 2016
Accepted: Dec 21, 2016
Published online: Mar 31, 2017
Discussion open until: Aug 31, 2017
Published in print: Oct 1, 2017
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