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Post-yielding tension stiffening of reinforced concrete members using an image analysis method with a consideration of steel ratios

  • Lee, Jong-Han (Department of Civil Engineering, Inha University) ;
  • Jung, Chi-Young (Seismic Simulation Test Center, Pusan National University) ;
  • Woo, Tae-Ryeon (Department of Civil Engineering, Pusan National University) ;
  • Cheung, Jin-Hwan (Department of Civil Engineering, Pusan National University)
  • Received : 2018.06.01
  • Accepted : 2019.03.20
  • Published : 2019.04.25

Abstract

When designing reinforced concrete (RC) members, the rebar is assumed to resist all tensile forces, but the resistance of the concrete in the tension area is neglected. However, concrete can also resist tensile forces and increase the tensile stiffness of RC members, which is called the tension stiffening effect (TSE). Therefore, this study assessed the TSE, particularly after yielding of the steel bars and the effects of the steel ratio on the TSE. For this purpose, RC member specimens with steel ratios of 2.87%, 0.99%, and 0.59% were fabricated for uniaxial tensile tests. A vision-based non-contact measurement system was used to measure the behavior of the specimens. The cracks on the specimen at the stabilized cracking stage and the fracture stage were measured with the image analysis method. The results show that the number of cracks increases as the steel ratio increases. The reductions of the limit state and fracture strains were dependent on the ratio of the rebar. As the steel ratio decreased, the strain after yielding of the RC members significantly decreased. Therefore, the overall ductility of the RC member is reduced with decreasing steel ratio. The yielding plateau and ultimate load of the RC members obtained from the proposed equations showed very good agreement with those of the experiments. Finally, the image analysis method was possible to allow flexibility in expand the measurement points and targets to determine the strains and crack widths of the specimens.

Keywords

Acknowledgement

Supported by : National Research Foundation of Korea (NRF)

References

  1. Allam, S.M., Shoukry, M.S., Rashad, G.E. and Hassan, A.S. (2012), "Crack width evaluation for flexural rc members", Alexandria Eng. J., 51, 211-220. https://doi.org/10.1016/j.aej.2012.05.001
  2. Allam, S.M., Shoukry, M.S., Rashad, G.E. and Hassan, A.S. (2013), "Evaluation of tension stiffening effect on the crack width calculation of flexural rc member", Alexandria Eng. J., 52, 163-173. https://doi.org/10.1016/j.aej.2012.12.005
  3. Balazs, G.L. (1993), "Cracking analysis based on slip and bond stresses", Am. Concrete Inst.: Mater. J., 90, 320-348.
  4. Belarbi, A. and Hsu, T.T.C. (1994), "constitutive laws of concrete in tension and reinforcing bars stiffened by concrete", Am. Concrete Inst.: Struct. J., 91, 465-474.
  5. Collins, M.P. and Mitchell, D. (1991), Prestressed Concrete Structures, Prentice Hall, New Jersey, UK.
  6. Committee Euro-International Du Beton (2013), CEB-FIP Model Code 2010, Design Code, Thomas Telford, Paris, France.
  7. Eurocode 2 (2010), Design of Concrete Structures-Part 1-1: General Rules and Rules for Buildings, CEN/TC250, EN 1992-1-1.
  8. Feng, D. and Feng, M.Q. (2016), "Vision-based multipoint displacement for structural health monitoring", Struct. Control Hlth. Monit., 23, 876-890. https://doi.org/10.1002/stc.1819
  9. Fukuda, Y., Feng, M.Q., Narita, Y., Kaneko, S. and Tanaka, T. (2013), "Vision-based displacement sensor for monitoring dynamic response using robust object search algorithm", IEEE Sens. J., 13, 4725-4732. https://doi.org/10.1109/JSEN.2013.2273309
  10. Gergely, P. and Lutz, L.A. (1968), "Maximum crack width in RC flexural members, causes, mechanism and control of cracking in concrete", SP-20 American Concrete Institute, Detroit, 87-117.
  11. Hassan, A.S. (2008), "Crack control for reinforced concrete members subjected to flexure", Master of Science Thesis, Alexandria University, Alexandria, Egypt.
  12. Johnson, A.I. (1951), "Deformation of reinforced concrete", Int. Assoc. Bridge Struct. Eng. Publ., 11, 253-290.
  13. Kang, S.B., Tan, K.H., Zhou, X.H. and Yang, B. (2017), "Influence of reinforcement ratio on tension stiffening of reinforced engineered cementitious composites", Eng. Struct., 141, 251-261. https://doi.org/10.1016/j.engstruct.2017.03.029
  14. Korean Highway Bridge Specifications (2012), Korean Ministry of Construction and Transportation.
  15. Lee, J.H., Ho, H.N., Shinozuka, M. and Lee, J.J. (2012), "An advanced bision-based system for real-time displacement measurement of high-rise buildings", Smart Mater. Struct., 21, 1-10.
  16. Lee, J.H., Jung, C.Y., Choi, E. and Cheung, J.H. (2017), "Visionbased multipoint measurement systems for structural in-plane and out-of-plane movements including twisting rotation", Smart Struct. Syst., 20(5), 563-572. https://doi.org/10.12989/SSS.2017.20.5.563
  17. Lee, S.C., Cho, J.Y. and Vecchio, F.J. (2011), "Model for postyield tension stiffening and rebar rupture in concrete members", Eng. Struct., 33, 1723-1733. https://doi.org/10.1016/j.engstruct.2011.02.009
  18. Lee, S.C., Cho, J.Y. and Vecchio, F.J. (2013), "Tension-stiffening model for steel fiber-reinforced concrete containing conventional reinforcement", Am. Concrete Inst.: Struct. J., 110, 639-648.
  19. Leonhardt, F. (1977), "Crack control in concrete structures", IABSE Surveys, No.S4/77, International Association for Bridges and Structural Engineering, Zurich.
  20. Lin, C.W., Hsu, W.K., Chiou, D.J., Chen, C.W. and Chiang, W.L. (2015), "Smart monitoring system with multi-criteria decision using a feature based computer vision technique", Smart Struct. Syst., 15, 1583-1600. https://doi.org/10.12989/sss.2015.15.6.1583
  21. Mondal, T.G. and Prakash, S.S. (2015), "Effect of tension stiffening on the behaviour of reinforced concrete circular columns under torsion", Eng. Struct., 92, 186-195. https://doi.org/10.1016/j.engstruct.2015.03.018
  22. Scanlon, A. and Murray, D.W. (1974), "Time-dependent reinforced concrete slab deflections", J. Struct. Div., ASCE, 100, 1911-1924. https://doi.org/10.1061/JSDEAG.0003881
  23. Scott, R.H. and Beeby, A.W. (2012), "Evaluation and management of tension stiffening", Am. Concrete Inst.: Spec. Publ., 284, 1-18.
  24. Structural Use of Concrete (1997), Code of Practice for Design and Construction, British Standards Institution: UK.
  25. Watstein, D. and Parsons, D.E. (1943), "Width and spacing of tensile cracks in axially reinforced concrete cylinders", J. Res. Nat. Bureau Stand., 31, 1-24. https://doi.org/10.6028/jres.031.001
  26. Welch, G.B. and Janjua, M.A. (1971), "Width and spacing of tensile cracks in reinforced concrete", UNICIV Report No R76, University of NSW, Kensington.
  27. Yankelevsky, D.Z., Jabareen, M. and Abutbul, A.D. (2008), "Onedimensional analysis of tension stiffening in reinforced concrete with discrete cracks", Eng. Struct., 30, 206-217. https://doi.org/10.1016/j.engstruct.2007.03.013
  28. Ye, X.W., Dong, C.Z. and Liu, T. (2016), "Force monitoring of steel cables using vision-based sensing technology: methodology and experimental verification", Smart Struct. Syst., 18, 585-599. https://doi.org/10.12989/sss.2016.18.3.585
  29. Ye, X.W., Ni, Y.Q., Wai, T.T., Wong, K.Y., Zhang, X.M. and Xu, F. (2013), "A vision-based system for dynamic displacement measurement of long-span bridges: algorithm and verification", Smart Struct. Syst., 12, 363-379. https://doi.org/10.12989/sss.2013.12.3_4.363

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