Advertisement

Materials and Structures

, Volume 48, Issue 4, pp 753–770 | Cite as

RILEM draft recommendation: TC-242-MDC multi-decade creep and shrinkage of concrete: material model and structural analysis*

Model B4 for creep, drying shrinkage and autogenous shrinkage of normal and high-strength concretes with multi-decade applicability
  • RILEM Technical Committee TC-242-MDC (Zdeněk P. Bažant, chair)
RILEM Technical Committee

Abstract

In response to the continuously advancing concrete technology, a new prediction model for creep and shrinkage is presented. This model, named B4, builds on the theoretically justified model B3, which is a RILEM recommendation from 1996. Improvements to the model allow for enhanced multi-decade prediction, distinguish between the drying and autogenous shrinkage, and introduce new equations and parameters to capture the effects of various admixtures and aggregate types. The development and justification of the model is described in three companion articles which follow.

Keywords

Material model Concrete creep Shrinkage Autogenous shrinkage 

Notes

Acknowledgments

Generous financial support from the U.S. Department of Transportation, provided through Grant 20778 from the Infrastructure Technology Institute of Northwestern University, is gratefully appreciated. So is an additional support under U.S. National Science Foundation Grants CMMI-1129449 and CMMI-1153494 to Northwestern University. Thanks are also due for additional financial support by the Austrian Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development and from the Austrian Science Fund (FWF) in the form of Erwin Schrödinger Scholarship J3619-N13. Valuable feedback on the final draft by Prof. V. Křístek is appreciated.

References

  1. 1.
    Bažant ZP, Yu Qiang, Li Guang-Hua (2012) Excessive long-time deflections of prestressed box girders: I. Record-span bridge in Palau and other paradigms. ASCE J Struct Eng 138(6):676–686CrossRefGoogle Scholar
  2. 2.
    Bažant ZP, Yu Qiang, Li Guang-Hua (2012) Excessive long-time deflections of collapsed prestressed box girders: II. Numerical analysis and lessons learned. ASCE J Struct Eng 138(6):687–696CrossRefGoogle Scholar
  3. 3.
    Bažant ZP, Hubler MH, Yu Q (2011) Pervasiveness of excessive segmental bridge deflections: Wake-up call for creep. ACI Struct J 108(6):766–774Google Scholar
  4. 4.
    Müller HS, Hilsdorf HK (1990) “Evaluation of the time-dependent behaviour of concrete: summary report on the work of the General Task Force Group No. 199.” CEB (Comité euro-internationale du béton), Lausanne, p 201Google Scholar
  5. 5.
    Hubler MH, Wendner R, Bažant ZP (2014) “Comprehensive database for concrete creep and shrinkage: analysis and recommendations for testing and recording.” ACI (in press)Google Scholar
  6. 6.
    Bažant ZP, Baweja S (1995) “Creep and shrinkage prediction model for analysis and design of concrete structures: Model B3.” RILEM Recommend Mater Struct 28:357–367 (Errata, 29:126)Google Scholar
  7. 7.
    Bažant ZP, Baweja S (2000) “Creep and shrinkage prediction model for analysis and design of concrete structures: model B3.” Adam Neville symposium: creep and shrinkage-structural design effects, ACI SP-194. Al-Manaseer A (ed) Am. Concrete Institute, Farmington Hills, Michigan, pp 1–83Google Scholar
  8. 8.
    Bažant ZP, Prasannan S (1989) Solidification theory for concrete creep. I: formulation. J Eng Mech ASCE 115(8):1691–1703CrossRefGoogle Scholar
  9. 9.
    Bažant ZP, Hauggaard AB, Baweja S, Ulm F-J (1997) Microprestress-solidification theory for concrete creep. I. Aging and drying effects. J Eng Mech ASCE 123(11):1188–1194CrossRefGoogle Scholar
  10. 10.
    Committee RILEM TC-69 (1988) “State of the art in mathematical modeling of creep and shrinkage of concrete.” In: Bažant ZP (ed) Mathematical modeling of creep and shrinkage of concrete, Wiley, New York, p 57–215Google Scholar
  11. 11.
    Jirásek M, Bažant ZP (2002) Inelastic analysis of structures. Wiley, New YorkGoogle Scholar
  12. 12.
    Yu Q, Bažant ZP, Wendner R (2012) Improved algorithm for efficient and realistic creep: analysis of large creep-sensitive concrete structures. ACI Struct J 109(5):665–676Google Scholar
  13. 13.
    Bažant ZP (1972) Prediction of concrete creep effects using age-adjusted effective modulus method. Am Concr Inst J 69:212–217Google Scholar
  14. 14.
    ACI Committee 435 (2003) “Control of deflection in concrete structures.” ACI 435R–95. Appendix BGoogle Scholar
  15. 15.
    Fédération Internationale du Béton (2010) Structural Concrete: Textbook on Behaviour, Design and Performance, vol 51. Int. du Béton, FIB-FédGoogle Scholar
  16. 16.
    Granger L (1995) Comportement différé du béton dans les enceintes de centrales nucléaires: analyse et modélisation, Ph.D. thesis, ENPC, Research Report, Laboratoire Centrale des Ponts et Chaussées, ParisGoogle Scholar
  17. 17.
    Navrátil J (1998) “Updating of prediction of creep and shrinkage of concrete” (In Czech: “Upřesnění predikce dotvarování a smrštování betonu”), Stavební obzor 7 (2), pp 44–50Google Scholar
  18. 18.
    ACI Committee 209 (2008) Guide for modeling and calculating shrinkage and creep in hardened concrete ACI Report 209.2R-08, Farmington HillsGoogle Scholar
  19. 19.
    Bažant ZP, Panula L (1978) “Practical prediction of time-dependent deformations of concrete.” Materials and structures (RILEM, Paris) 11, pp 307–316, 317–328, 415–424Google Scholar
  20. 20.
    Wang J, Yan P, Yu H (2007) “Apparent activiation energy of concrete in early age determined by adiabatic test.” J Wuhan Univ Tech Mater Sci 22(3), pp 537–541Google Scholar
  21. 21.
    Poole JL et al (2007) Methods for calculating activation energy for Portland cement. ACI Mater J 104(1):303–311Google Scholar
  22. 22.
    Hubler MH, Wendner R, Bažant ZP (2015) “Statistical justification of model B4 for drying and autogenous shrinkage of concrete and comparisons to other models.” RILEM Mater Struct. doi: 10.1617/s11527-014-0516-z
  23. 23.
    Wendner R, Hubler MH, Bažant ZP (2014) Optimization method, choice of form and uncertainty quantification of model B4 using laboratory and multi-decade bridge databases. RILEM Mater Struct. doi: 10.1617/s11527-014-0515-0
  24. 24.
    Müller HS, Anders IB, Reiner R Vogel M (2013) “Concrete: treatment of types and properties in fib Model Code 2010”, Structural Concrete 14(4):320–334Google Scholar
  25. 25.
    Nasser KW, Al-Manaseer A (1986) Creep of concrete containing fly ash and superplasticizer at different stress/strength ratios. Am Concr Inst J 62:668–673Google Scholar
  26. 26.
    Bažant ZP, Kim J-K, Panula L (1992) Improved prediction model for time dependent deformations of concrete Part 5 -cyclic load and cyclic humidity. Mater Struct 25:163–169CrossRefGoogle Scholar
  27. 27.
    Bažant ZP, Donmez A (2015) "Extrapolation of short-time drying shrinkage tests based on measured diffusion size effect: concept and reality." Mater Struct. doi: 10.1617/s11527-014-0507-0
  28. 28.
    Bažant ZP, Hubler MH (2014) “Theory of cyclic creep of concrete based on Paris law for fatigue growth of subcritical microcracks.” J Mech Phys Solids 63:187–200Google Scholar

Copyright information

© RILEM 2015

Authors and Affiliations

  • RILEM Technical Committee TC-242-MDC (Zdeněk P. Bažant, chair)
    • 1
  1. 1.Northwestern UniversityEvanstonUSA

Personalised recommendations