Structural Engineering and Mechanics

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Bond mechanism of 18-mm prestressing strands: New insights and design applications

  • Dang, Canh N. (Department for Management of Science and Technology Development, Ton Duc Thang University) ;
  • Marti-Vargas, Jose R. (Institute of Concrete Science and Technology (ICITECH), Universitat Politecnica de Valencia) ;
  • Hale, W. Micah (University of Arkansas, Department of Civil Engineering)
  • Received : 2019.12.02
  • Accepted : 2020.05.18
  • Published : 2020.10.10
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Abstract

Pretensioned concrete (PC) is widely used in contemporary construction. Bond of prestressing strand is significant for composite-action between the strand and concrete in the transfer and flexural-bond zones of PC members. This study develops a new methodology for quantifying the bond of 18-mm prestressing strand in PC members based on results of a pullout test, the Standard Test for Strand Bond (STSB). The experimental program includes: (a) twenty-four pretensioned concrete beams, using a wide range of concrete compressive strength; and (b) twelve untensioned pullout specimens. By testing beams, the transfer length, flexural-bond length, and development length were all measured. In the STSB, the pullout forces for the strands were measured. Experimental results indicate a significant relationship between the bond of prestressing strand to the code-established design parameters, such as transfer length and development length. However, the code-predictions can be unconservative for the prestressing strands having a low STSB pullout force. Three simplified bond equations are proposed for the design applications of PC members.

Keywords

Acknowledgement

This research is supported by the University of Arkansas at Fayetteville and the Ton Duc Thang University. The authors would like to thank Insteel Industries Inc. for providing the strands for this research. The authors also would like to thank a number of individuals at the University of Arkansas for their contribution in this study.

References

  1. AASHTO (2017), Load and Resistance Factor Design for Highway Bridges Specifications (AASHTO-LRFD), American Association of State Highway and Transportation Officials; Washington D.C., USA.
  2. Abdelatif, A.O., Owen, J.S. and Hussein, M.F. (2015), "Modelling the prestress transfer in pre-tensioned concrete elements", Finite Elem. Anal. Des., 94, 47-63. https://doi.org/10.1016/j.finel.2014.09.007.
  3. Abrishami, H.G. and Mitchell, D. (1993), "Bond characteristics of pretensioned strand", ACI Mat. J., 90(3), 228-235.
  4. ACI (2019), Building Code Requirements for Structural Concrete and Commentary (ACI 318-19), American Concrete Institute; Farmington Hills, MI, USA.
  5. Arab, A.A., Badie, S.S. and Manzari, M.T. (2011), "A methodological approach for finite element modeling of pretensioned concrete members at the release of pretensioning", Eng. Struct., 33(6), 1918-1929. https://doi.org/10.1016/j.engstruct.2011.02.028.
  6. ASTM (2015), Standard Test Method for Evaluating Bond of Seven-Wire Steel Prestressing Strand (ASTM A1081), American Society for Testing and Materials; West Conshohocken, PA, USA.
  7. ASTM (2018), Standard Specification for Steel Strand, Uncoated Seven-Wire for Prestressed Concrete (ASTM A416), American Society for Testing and Materials; West Conshohocken, PA. USA.
  8. Bai, F. and Davidson, J.S. (2016), "Composite beam theory for pretensioned concrete structures with solutions to transfer length and immediate prestress losses", Eng. Struct., 126, 739-758. https://doi.org/10.1016/j.engstruct.2016.08.031.
  9. Balazs, G.L. (1992), "Transfer control of prestressing strands", PCI J., 37(6), 60-71. https://doi.org/10.15554/pcij.11011992.60.71
  10. Barakat, S., Al-Toubat, S., Leblouba, M. and Al Burai, E. (2019), "Behavioral trends of shear strengthened reinforced concrete beams with externally bonded fiber-reinforced polymer", Struct. Eng. Mech., 69(5), 579-589. https://doi.org/10.12989/sem.2019.69.5.579.
  11. Barnes, R.W., Grove, J.W. and Burns, N.H. (2003), "Experimental assessment of factors affecting transfer length", ACI Struct.J., 100(6), 740-748.
  12. Briere, V., Harries, K.A., Kasan, J. and Hager, C. (2013), "Dilation behavior of seven-wire prestressing strand-The Hoyer effect", Constr. Build. Mater., 40, 650-658. https://doi.org/10.1016/j.conbuildmat.2012.11.064.
  13. Buckner, C.D. (1995), "A review of strand development length for pretensioned concrete members", PCI J., 40(2), 84-99. https://doi.org/10.15554/pcij.03011995.84.105
  14. Caro, L., Marti-Vargas, J.R. and Serna, P. (2013), "Time-dependent evolution of strand transfer length in pretensioned prestressed concrete members", Mech. Time-Depend. Mat., 17(4), 501-527. https://doi.org/10.1007/s11043-012-9200-2.
  15. CEN (2004), Eurocode 2: Design of Concrete Structures: Part 1-1: General Rules and Rules for Buildings (EC2), European Committee for Standardization; Brussels, Belgium.
  16. Dang, C.N., Floyd, R.W., Hale, W.M. and Marti-Vargas, J.R. (2016a), "Measured development lengths of 0.7 in. (17.8 mm) strands for pretensioned beams", ACI Struct. J., 113(3), 525-535.
  17. Dang, C.N., Floyd, R.W., Hale, W.M. and Marti-Vargas, J.R. (2016b), "Measured transfer lengths of 0.7 in. (17.8 mm) strands for pretensioned beams", ACI Struct. J., 113(1), 85-94.
  18. Dang, C.N., Floyd, R.W., Murray, C.D., Hale, W.M. and Marti-Vargas, J.R. (2015), "Bond stress-slip model for 0.6 in. (15.2 mm) diameter strand", ACI Struct. J., 112(5), 625-634. https://doi.org/10.14359/51687750
  19. Dang, C.N., Murray, C.D., Floyd, R.W., Hale, W.M. and Marti-Vargas, J.R. (2014a), "Analysis of bond stress distribution for prestressing strand by Standard Test for Strand Bond", Eng. Struct., 72, 152-159. https://doi.org/10.1016/j.engstruct.2014.04.040.
  20. Dang, C.N., Murray, C.D., Floyd, R.W., Hale, W.M. and Marti-Vargas, J.R. (2014b), "A correlation of strand surface quality to transfer length", ACI Struct. J., 111(5), 1245-1252. https://doi.org/10.14359/51686925
  21. Den Uijl, J.A. (1998), "Bond modelling of prestressing strand", ACI Special Publication, 180, 145-170.
  22. FIB (2013), Model Code for Concrete Structures 2010 (MC 2010), International Federation for Structural Concrete; Lausanne, Switzerland.
  23. Janney, J.R. (1954), "Nature of bond in pre-tensioned prestressed concrete", ACI J., 25(9), 717-737.
  24. Jiang, X., Cabage, J., Jing, Y., Ma, Z. J. and Burdette, E.G. (2017), "Effect of embedment length on bond of 18 mm (0.7 in.) strand by pullout test", ACI Struct. J., 114(3), 707-717. https://doi.org/10.14359/51689442
  25. Kareem, R.S., Al-Mohammedi, A., Dang, C.N., Marti-Vargas, J.R. and Hale, W.M. (2019), "Bond model of 15.2-mm strand with consideration of concrete creep and shrinkage", 72(15), Mag. Concr. Res., 799-810. https://doi.org/ 10.1680/jmacr.18.00506.
  26. Lee, C., Lee, S. and Shin, S. (2017), "Modeling of transfer region with local bond-slip relationships", ACI Struct. J., 114(1), 187-196. https://doi.org/10.14359/51689253
  27. Llau, A., Jason, L., Dufour, F. and Baroth, J. (2016), "Finite element modelling of 1D steel components in reinforced and prestressed concrete structures", Eng. Struct., 127, 769-783. https://doi.org/10.1016/j.engstruct.2016.09.023.
  28. Marti-Vargas, J.R., Arbelaez, C.A., Serna-Ros, P., Navarro-Gregori, J. and Pallares-Rubio, L. (2007), "Analytical model for transfer length prediction of 13 mm prestressing strand", Struct. Eng. Mech., 26(2), 211-229. https://doi.org/10.12989/sem.2007.26.2.211.
  29. Marti-Vargas, J.R., Caro, L.A. and Serna, P. (2014a), "Size effect on strand bond and concrete strains at prestress transfer", ACI Struct. J., 111(2), 419-429.
  30. Marti-Vargas, J.R., Garcia-Taengua, E., Caro, L.A. and Serna, P. (2014b), "Measuring specific parameters in pretensioned concrete members using a single testing technique", Measurement, 49, 421-432. https://doi.org/10.1016/j.measurement.2013.12.007.
  31. Marti-Vargas, J.R., Garcia-Taengua, E. and Serna, P. (2013), "Influence of concrete composition on anchorage bond behavior of prestressing reinforcement", Constr. Build. Mater., 48, 1156-1164. https://doi.org/10.1016/j.conbuildmat.2013.07.102.
  32. Marti-Vargas, J.R., Hale, W.M., Garcia-Taengua, E. and Serna, P. (2014c), "Slip distribution model along the anchorage length of prestressing strands", Eng. Struct., 59, 674-685. https://doi.org/10.1016/j.engstruct.2013.11.032.
  33. Mitchell, D., Cook, W.D., Khan, A.A. and Tham, T. (1993), "Influence of high strength concrete on transfer and development length of pretensioning strand", PCI J., 38(3), 52-66. https://doi.org/10.15554/pcij.05011993.52.66
  34. Morcous, G., Assad, S., Hatami, A. and Tadros, M.K. (2014), "Implementation of 0.7 in. diameter strands at 2.0$\times$ 2.0 in. spacing in pretensioned bridge girders", PCI J., 59(3), 145-158. https://doi.org/10.15554/pcij.06012014.145.158
  35. Morcous, G., Hatami, A., Maguire, M., Hanna, K. and Tadros, M. (2012), "Mechanical and Bond properties of 18-mm- (0.7-in.-) diameter prestressing strands", J. Mat. Civil Eng., 24(6), 735-744. https://doi.org/10.1061/(ASCE)MT.1943-5533.0000424.
  36. Motwani, P. and Laskar, A. (2019), "Influence of excessive end slippage on transfer length of prestressing strands in PC members", Structures, 20, 676-688. https://doi.org/10.1016/j.istruc.2019.05.004.
  37. Moustafa, S.E. (1974), "Pull-out strength of strand and lifting loops", Research Report No. 74-B5; Concrete Technology Associates, Tacoma, WA, USA.
  38. Myers, J.J., Volz, J.S., Sells, E., Porterfield, K., Looney, T., Tucker, B. and Holman, K. (2012), "Report B: Self-Consolidating Concrete (SCC) for infrastructure elements: bond, transfer length and development length of prestressing strand in SCC", Research Report No. CMR 13-003 (Report B); Missouri Department of Transportation, Missouri University of Science and Technology, MO, USA.
  39. Naji, B., Ross, B.E. and Floyd, R.W. (2016), "Characterization of bond-loss failures in pretensioned concrete girders", J. Bridge Eng., 22(4), 1-6. https://doi.org/10.1061/(ASCE)BE.1943-5592.0001025.
  40. Oh, B.H., Lim, S.N., Lee, M.K. and Yoo, S.W. (2014), "Analysis and prediction of transfer length in pretensioned, prestressed concrete members", ACI Struct. J., 111(6), 1-12.
  41. Ortega, N.F., Moro, J.M. and Meneses, R.S. (2018), "Theoretical model to determine bond loss in prestressed concrete with reinforcement corrosion", Struct. Eng. Mech, 65(1), 1-7. https://doi.org/10.12989/sem.2018.65.1.001.
  42. Osborn, A.E.N., Lawler, J.S. and Connolly, J.D. (2008), "Acceptance tests for surface characteristics of steel strands in prestressed concrete", Research Report No. NCHRP 621; Transportation Research Board, Washington D.C., USA.
  43. Park, H. and Cho, J. (2014), "Bond-slip-strain relationship in transfer zone of pretensioned concrete elements", ACI Struct. J., 111(3), 503-514. https://doi.org/10.14359/51686567
  44. Ramirez, J.A. and Russell, B.W. (2008), "Transfer, development and splice length for strand/reinforcement in high strength concrete", Research Report No. NCHRP 603; Transportation Research Board, Washington D.C., USA.
  45. Ramirez-Garcia, A.T., Dang, C.N., Hale W.M. and Marti-Vargas, J.R. (2017), "A higher-order equation for modeling strand bond in pretensioned concrete beams", Eng. Struct., 131, 345-361. https://doi.org/10.1016/j.engstruct.2016.10.050.
  46. Riding, K.A., Peterman, R.J. and Polydorou, T. (2016), "Establishment of minimum acceptance criterion for strand bond as measured by ASTM A1081", PCI J., 61(3), 86-103.
  47. Russell, B.W. (2006), "NASP round IV strand bond testing", Final Report; Oklahoma State University, OK, USA.
  48. Russell, B.W. and Burns, N.H. (1993), "Design guidelines for transfer, development and debonding of large diameter seven wire strands in pretensioned concrete girders", Research Report No. FHWA/TX-93+1210-5F; Texas Department of Transportation, Austin, TX, USA.
  49. Shahawy, M. (2001), "A critical evaluation of the AASHTO provisions for strand development length of prestressed concrete members", PCI J., 46(4), 94-117. https://doi.org/10.15554/pcij.07012001.94.117
  50. Steensels, R., Vandewalle, L., Vandoren, B. and Degee, H. (2017), "A two-stage modelling approach for the analysis of the stress distribution in anchorage zones of pre-tensioned, concrete elements", Eng. Struct., 143, 384-397. https://doi.org/10.1016/j.engstruct.2017.04.0.
  51. Tang, C.W. (2018), "Local bond-slip behavior of medium and high strength fiber reinforced concrete after exposure to high temperatures", Struct. Eng. Mech., 66(4), 477-485. https://doi.org/10.12989/sem.2018.66.4.477.
  52. Trejo, D., Hueste, M.B.D., Kim, Y.H. and Atahan, H. (2008), "Characterization of self-consolidating concrete for design of precast, prestressed bridge girders", Research Report No. FHWA/TX-09/0-5134-2, Transportation Research Board, Washington D.C., USA.
  53. Van Meirvenne, K., De Corte, W., Boel, V. and Taerwe, L. (2018), "Non-linear 3D finite element analysis of the anchorage zones of pretensioned concrete girders and experimental verification", Eng. Struct., 172, 764-779. https://doi.org/10.1016/j.engstruct.2018.06.065.
  54. Warenycia, K., Diaz-Arancibia, M. and Okumus, P. (2017), "Effects of confinement and concrete nonlinearity on transfer length of prestress in concrete", Structures, 11, 11-21. https://doi.org/10.1016/j.istruc.2017.04.002.
  55. Yapar, O., Basu, P. 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.