Mechanical Properties of Steel-FRP Composite Bar under Uniaxial and Cyclic Tensile Loads
Publication: Journal of Materials in Civil Engineering
Volume 22, Issue 10
Abstract
This paper introduces a newly developed steel-fiber-reinforced polymer (FRP) composite bar (SFCB) and proposes the ideal configuration based on a large number of exploratory tests on handmade products. Based on factory production of SFCB, uniaxial tensile tests and cyclic tensile tests were conducted to determine the initial elastic modulus, postyield stiffness, yield strength, ultimate strength, unloading stiffness, and residual deformation. Test results showed that the stress-strain curve of the SFCB was bilinear before the fiber fractures. After the inner steel yielded, the SFCB showed a stable postyield stiffness, small residual deformation, and good reparability. Because the theoretical model for the stress-strain curve of SFCB under a uniaxial load based on the mixture rule had large error with data from cyclic tests, the corresponding restoring force model under cyclic tensile loading was constructed by statistical analysis of the stress-strain test curve under cyclic tension. The generated restoring force model accurately displayed the trend of unloading stiffness of SFCB degradation with cyclic loads. Furthermore, the predicted results were in good agreement with the experimental results, which proved that the mechanical properties of SFCB could be predicted and designed by the proposed model.
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Acknowledgments
The writers would like to acknowledge financial support from the National Basic Research Program of China (973 Program) (Grant No. UNSPECIFIED2007CB714200), the National Natural Science Foundation of China (Grant No. NNSFC50608015), the National Key Technology R&D Program of China in the 11th Five-Year Period (Grant No. UNSPECIFIED2006BAJ03B07), and the Natural Science Foundation of Jiangsu Province, China (Grant No. UNSPECIFIEDBK2009288).
References
American Concrete Institute (ACI). (2003). “Guide for the design and construction of concrete reinforced with FRP bars.” ACI 440. 1R-0, Detroit.
Christopoulos, C., and Pampanin, S. (2004). “Towards performance-based seismic design of MDOF structures with explicit consideration of residual deformations.” ISET J. Earthquake Technol., 41(1), 53–73.
Christopoulos, C., Pampanin, S., and Priestley, M. J. (2003). “Performance-based seismic response of frame structures including residual deformations. Part I: Single-degree of freedom systems.” J. Earthquake Eng., 7(1), 97–118.
Chung, Y. S., Park, C. K., and Yer, C. M. (2008). “Residual seismic performance of reinforced concrete bridge piers after moderate earthquakes.” ACI Struct. J., 105(1), 87–95.
Clough, R. W., and Johnston, S. B. (1966). “Effect of stiffness degradation on earthquake ductility requirements.” Proc., 2nd Japan Earthquake Eng. Symp., Tokyo, 227–232.
Iemura, H., Takahashi, Y., and Sogabe, N. (2002). “Innovation of high-performance RC structure with unbonded bars for strong earthquankes.” Trans. Jpn. Soc. Civ. Eng., 710, 283–296.
Iemura, H., Takahashi, Y., and Sogabe, N. (2006). “Two-level seismic design method using post-yield stiffness and its application to unbonded bar reinforced concrete piers.” Struct. Eng./Earthquake Eng., 23(1), 109s–116s.
Jacob, A. (2004). “Pultrusion update.” Reinf. Plast., 48(6), 30–32.
Kawashima, K., MacRae, G. A., Hoshikuma, J., and Nagaya, K. (1998). “Residual displacement response spectrum.” J. Struct. Eng., 124(5), 523–530.
Mazzoni, S., McKenna, F., Scott, M. H., Fenves, G. L., and Jeremic, B. (2003). “Opensees command language manual.” Pacific Earthquake Engineering Research Center, Univ. of Calif., Berkeley, ⟨http://opensees.berkeley.edu⟩ (Jan. 12, 2008).
Restrepo-Posada, J. I., Dodd, L. L., Park, R., and Cooke, N. (1994). “Variables affecting cyclic behavior of reinforcing steel.” J. Struct. Eng., 120(11), 3178–3196.
Rizkalla, S., and Hassan, T. (2002). “Effectiveness of FRP for strengthening concrete bridges.” Struct. Eng. Int. J. Int. Assoc. Bridge Struct. Eng., 12(2), 89–95.
Sakai, J., and Mahin, S. A. (2004). “Analytical investigations of new methods for reducing residual displacements of reinforced concrete bridge columns.” Rep. No. PEER 2004/02, Pacific Earthquake Engineering Research Center, Univ. of California at Berkeley, Berkeley, Calif.
Wu, G., Wu, Z. S., Luo, Y. B., and Wei, H. C. (2009). “A new reinforcement material of steel fiber composite bar (SFCB) and its mechanics properties.” Proc., 9th Int. Symp. on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures (FRPRCS-9), Sydney, Australia.
Wu, Y. F. (2006). “New avenue of achieving ductility for reinforced concrete members.” J. Struct. Eng., 132(9), 1502–1506.
Wu, Y. F. (2008). “Ductility demand of compression yielding fiber-reinforced polymer-reinforced concrete beams.” ACI Struct. J., 105(1), 104–110.
Wu, Z. S., Sakamoto, K., Niu, H. D., and Kurokawa, T. (2001). “Retrofitting RC beams with innovative hybrid fiber sheets.” Proc., 7th Japan Int. SAMPE Symp., Tokyo, 383–386.
Wu, Z. S., Wu, G., and Lv, Z. T. (2006). “Earthquake-resistant concrete structures reinforced by steel-FRP composite bar.” China national invention patent, publication no. CN1936206, Beijing, China (in Chinese).
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 22 • Issue 10 • October 2010
Pages: 1056 - 1066
Copyright
© 2010 ASCE.
History
Received: Jun 19, 2009
Accepted: Apr 12, 2010
Published online: Apr 15, 2010
Published in print: Oct 2010
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