Structural Engineering and Mechanics

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Simulations of short- and long-term deflections of flat plates considering effects of construction sequences

  • Kim, Jae-Yo (Department of Architectural Engineering, Kwangwoon University) ;
  • Kang, Su-Min (Department of Architectural Engineering, Chungbuk National University)
  • Received : 2015.01.14
  • Accepted : 2017.02.10
  • Published : 2017.05.25
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Abstract

The structural designs of RC flat plates that have no flexural stiffness by boundary beams may be governed not by strength conditions but by serviceabilities. Specially, since over-loading and tensile cracking in early-aged slabs significantly increase the short- and long-term deflections of a flat plate system, a construction sequence and its impact on the slab deflections may be decisive factors in designs of flat plate systems. In this study, the procedure of simulating slab deflections with considering construction sequences, concrete cracking, and long-term effects is proposed. The proposed method is practically useful, as it can predict well the slab deflections at construction and service stages only with a few input data. The proposed method is verified by comparisons with measured results in a real-scale test.

Keywords

Acknowledgement

Supported by : Kwangwoon University

References

  1. ACI Committee 318 (2011), Building code requirement for structural concrete (ACI 318-11), American Concrete Institute. Farmington Hills, MI.
  2. ACI Committee 435 (2003), Control of Deflection in Concrete Structures (ACI 435R-95), American Concrete Institute. Farmington Hills, MI.
  3. CEB-FIP (1993), CEB-FIP Model Code 1990, Design Code, Comite Euro-International, Thomas Telford.
  4. Chang, K.Y. and Hwang, S.J. (1996), "Practical estimation of twoway slab deflections", J. Struct. Eng., ASCE, 122(2), 150-159. https://doi.org/10.1061/(ASCE)0733-9445(1996)122:2(150)
  5. Choi, S.H., Ju, H., Lee, D.H., Kim, K.S., Lee, J.Y. and Shin, M. (2014), "Unified equivalent frame method for flat plate slab structures under combined gravity and lateral loads-Part 2: verification", Earthq. Struct., 7(5), 735-751. https://doi.org/10.12989/eas.2014.7.5.735
  6. Chung, K.M., Chou C.C., Chang, K.C. and Chen, Y.J. (2013), "Effect of a vertical guide plate on the wind loading of an inclined flat plate", Wind Struct., 17(5), 537-552. https://doi.org/10.12989/was.2013.17.5.537
  7. Gardner, N.J. and Fu, H.C. (1987), "Effects of high construction loads on the long-term deflections of flat slabs", ACI Struct. J., 84(3), 349-360.
  8. Tian, Y., Chen, J., Said, A. and Zhao, J. (2012), "Nonlinear modeling of flat-plate structures using grid beam elements", Comput. Concrete, 10(5), 489-505. https://doi.org/10.12989/cac.2012.10.5.489
  9. Hossain, T.R. and Vollum, R.L. (2002), "Prediction of slab deflection and validation against cardington data", Proc. Inst. Civ. Engineers, Struct. Build., 152(3), 235-247. https://doi.org/10.1680/stbu.2002.152.3.235
  10. Hwang, H.J., Park, H.G., Hong, G.H., Kim, J.Y. and Kim, Y.N. (2016), "Time-dependent deflection of slab affected by construction load", ACI Struct. J., 113(3), 557-566.
  11. Kang, S.M., Eom, T.S. and Kim, J.Y. (2013), "Reshoring effects on deflections of multi-shored flat plate systems under construction", Struct. Eng. Mech., 45(4), 455-470. https://doi.org/10.12989/sem.2013.45.4.455
  12. Kim, K.S., Choi, S.H., Ju, H., Lee, D.H., Lee, J.Y. and Shin, M. (2014), "Unified equivalent frame method for flat plate slab structures under combined gravity and lateral loads-Part 1: derivation", Earthq. Struct., 7(5), 719-733. https://doi.org/10.12989/eas.2014.7.5.719
  13. Lee, J.I., Scanlon, A. and Scanlon, M.A. (2007), "Effect of early age loading on time-dependent deflection and shrinkage restraint cracking of slabs with low reinforcement ratios", ACI Spec. Pub., 246, 149-166.
  14. Lee, Y.H. and Scanlon, A. (2010), "Comparison of one-and twoway slab minimum thickness provisions in building codes and standards", ACI Struct. J., 107(2), 157-163.
  15. Lee, Y.H., Kim, M.S., Lee, J. and Scanlon, A. (2013), "Comparison of minimum thickness provisions for concrete beams in building codes and standards", Can. J. Civ. Eng., 40(7), 595-602. https://doi.org/10.1139/cjce-2012-0479
  16. Mirzaei, Y. and Sasani, M. (2013), "Progressive collapse resistance of flat slabs: modeling post-punching behavior", Comput. Concrete, 12(3), 351-375. https://doi.org/10.12989/cac.2013.12.3.351
  17. Park, H.G., Hwang, H.J., Hong, G.H., Kim, Y.N. and Kim, J.Y. (2011), "Slab construction load affected by shore stiffness and concrete cracking", ACI Struct. J., 108(6), 679-688.
  18. Park, H.G., Hwang, H.J., Hong, G.H., Kim, Y.N. and Kim, J.Y. (2012), "Immediate and long-term deflections of reinforced concrete slabs affected by early-age loading and low temperature", ACI Struct. J., 109(3), 413-422.
  19. Puente, I., Azkune, M. and Insausti, A. (2007), "Shore-slab interaction in multistory reinforced concrete buildings during construction: an experimental approach", Eng. Struct., 29(5), 731-741. https://doi.org/10.1016/j.engstruct.2006.06.018
  20. Rangan, B.V. (1976), "Prediction of long-term deflections of flat plates and slabs", ACI J., 73(4), 223-226.
  21. Scanlon, A. and Murray, D.W. (1982), "Practical calculation of two-way slab deflections", Concrete International, November 43-50.
  22. Stivaros, P.C. and Halvorsen, G.T. (1990), "Shoring/reshoring operations for multistory building", ACI Struct. J., 87(5), 589-596.
  23. Vollum, R.L. and Afshar A. (2009), "Influence of construction loading on deflections in reinforced concrete slabs", Magaz. Concrete Res., 61(1), 3-14. https://doi.org/10.1680/macr.2009.61.1.3
  24. Vollum, R.L., Moss, R.M. and Hossain, T.R. (2002), "Slab deflection in the cardington in-situ concrete frame building", Magaz. Concrete Res., 54(1), 23-34. https://doi.org/10.1680/macr.2002.54.1.23

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