Computers and Concrete

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Strengthening of prestressed girder-deck system with partially debonding strand by the use of CFRP or steel plates: Analytical investigation

  • Haoran Ni (Department of Civil and Environmental Engineering, Syracuse University) ;
  • Riliang Li (Department of Civil and Environmental Engineering, Syracuse University) ;
  • Riyad S. Aboutaha (Department of Civil and Environmental Engineering, Syracuse University)
  • Received : 2022.12.15
  • Accepted : 2023.01.27
  • Published : 2023.04.25
⟨ Previous Next ⟩

Abstract

This paper describes an in-depth analysis on flexural strength of a girder-deck system experiencing a strand debonding damage with various strengthening systems, based on finite element software ABAQUS. A detailed finite element analysis (FEA) model was developed and verified against the relevant experimental data performed by other researchers. The proposed analytical model showed a good agreement with experimental data. Based on the verified FE model, over a hundred girder-deck systems were investigated with the consideration of following variables: 1) debonding level, 2) span-to-depth ratio (L/d), 3) strengthening type, 4) strengthening material thickness. Based on the data above, a new detailed analytical model was developed and proposed for estimating residual flexural strength of the strand-debonding damaged girder-deck system with strengthening systems. It was demonstrated that both finite element model and analysis model could be used to predict flexural behaviors for debonding damaged prestressed girder-deck systems. Since the strands are debonding from surrounding concrete over a certain zone over the length of the beam, the increase of strain in strands can be linked with a ratio ψ, which is Lp/c. The analytical model was proposed and developed regarding the ratio ψ. By conducting procedure of calculating ψ, the ψ value varies from 9.3 to 70.1. Multiple nonlinear regression analysis was performed in Software IBM SPSS Statistics 27.0.1 to derive equation of ψ. ψ equation was curved to be an exponential function, and the independent variable (X) is a linear function in terms of three variables of debonding level (λ), span length (L), and amount of strengthening material (As). The coefficient of determinate (R2) for curve fitting in nonlinear regression analysis is 0.8768. The developed analytical model was compared to the ultimate capacities computed by FEA model.

Keywords

Acknowledgement

The author is truly grateful to the support of funding and computational facilities provided by the Department of Civil and Environmental Engineering at Syracuse University.

References

  1. AASHTO LRFD (2020), AASHTO LRFD Bridge Design Specifications, 9th Edition, American Association of State Highway and Transportation Officials, Washington, D.C., USA.
  2. ABAQUS (2016), ABAQUS User's Manual, Dassault Systemes Simulia Corp, Providence, RI, USA.
  3. Arab, A.A., Badie, S.S. and Manzari, M.T. (2011), "A methodology approach for finite element modeling of pretensioned concrete members at the release of pretensioning," Eng. Struct., 33, 1918-1929. https://doi.org/10.1016/j.engstruct.2011.02.028.
  4. Au, F.T.K. and Du, J.S., (2004) "Prediction of ultimate stress in unbonded prestressed tendons", Mag. Concrete Res., 56, 1-11. https://doi.org/10.1680/macr.56.1.1.36288.
  5. Bai, T., Yan, B., Ataei, H. and Aboutaha, R. (2016), "Strength and ductility of CFRP strengthened highway PC girders: An FEM investigation", 8th International Conference on Fiber-Reinforced Polymer (FRP) Composites in Civil Engineering, CICE 2016, Hong Kong, China, December.
  6. ElSafty, A., Graeff, M.K. and Fallaha, S., (2014), "Behavior of laterally damaged prestressed concrete bridge girders repaired with CFRP laminates under static and fatigue loading", Int. J. Concrete Struct. Mater., 8(1), 43-59. https://doi.org/10.1007/s40069-013-0053-0.
  7. Harajli, M.H. (2006), "On the stress in unbonded tendons at ultimate: Critical assessment and proposed changes", ACI Struct. J., 103(6), 803-812. https://doi.org/10.14359/18231.
  8. Jnaid, F. and Aboutaha, R.S. (2014), "Residual flexural strength of reinforced concrete beams with debonding reinforcement", ACI Struct. J., 111(6), 1419-1430. https://doi.org/10.14359/51686975.
  9. Kaklauskas, G. and Ghaboussi, J. (2001), "Stress-strain relations for cracked tensile concrete from RC beam tests," J. Struct. Eng., 127, 64-73. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:1(64).
  10. Kang, T. and Huang, Y. (2012), "Computer modeling of posttensioned structures", 4th International Conference on Computer Modeling and Simulation, Hong Kong, China, February.
  11. Meski, F. and Harajli, M. (2013), "Flexural behavior of debonding posttensioned concrete members strengthened using external FRP composites", J. Compos. Constr., 17(2), 197-207. https://doi.org/10.1061/(ASCE).
  12. Ozkul, O., Nassif, H., Tanchan, P. and Harajli, M. (2008), "Rational approach for predicting stress in beams with debonding tendons", ACI Struct. J., 105, 338-347. https://doi.org/10.14359/19793.
  13. PCI (2020), Precast and Prestressed Concrete Handbook, 7th Edition, Precast/Prestressed Concrete Institute, Chicago, IL, USA.
  14. Yan, B. (2019), "Residual flexural strength of corroded AASHTO Type II pretensioned concrete girder-deck system", Ph.D. Dissertation, Syracuse University, Syracuse, NY, USA.
  15. Yang, K.H. and Kang, T.H.K. (2011), "Equivalent strain distribution factor for debonding tendon stress at ultimate", ACI Struct. J., 108, 217-226. https://doi.org/10.14359/51664257.
  16. Yang, K.H., Mun, J.H., Cho, M.S. and Kang, T.H.K. (2014), "Stress-strain model for various unconfined concretes in compression", ACI Struct. J., 111, 819-826. https://doi.org/10.14359/51686631.
  17. Yapar, O., Basu, P.K. and Nordendale, N. (2015), "Accurate finite element modeling of pretensioned prestressed concrete beams", Eng. Struct., 101, 163-178. https://doi.org/10.1016/j.engstruct.2015.07.018.