- Volume 7 Issue 4
Predictions about shrinkage and creep of concrete are very important for evaluating time-dependent effects on structural performance. Some prediction models and formulas of concrete shrinkage and creep have been proposed with diversity. However, the influence of reinforcement ratio on shrinkage and creep of concrete has been ignored in most prediction models and formulas. In this paper, the concrete shrinkage and creep with different ratios of reinforcement were studied. Firstly, the shrinkage performance was tested by the 10 reinforced concrete beams specimens with different reinforcement ratios for 200 days. Meanwhile, the creep performance was tested by the 5 reinforced concrete beams specimens with different ratios of reinforcement under sustained load for 200 days. Then, the test results were compared with the prediction models and formulas of CEB-FIP 90, ACI 209, GL 2000 and JTG D 62-2004. At last, based on ACI 209, an improved prediction models and formulas of concrete shrinkage and creep considering reinforcement ratio was derived. The results from improved prediction models and formulas of concrete shrinkage and creep are in good agreement with the experimental results.
concrete creep;concrete shrinkage;reinforcement ratio;prediction model
- ACI Committee 209 (1992), Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures, American Concrete Institute.
- Alvarado, Y.A., Buitrago, M., Gasch, I., Dominguez, M.N. and Cipagauta, M.A. (2017), "Short- and long-term deflections of RC building structures influenced by construction processes", Struct. Eng. Mech., 64(2), 173-181. https://doi.org/10.12989/sem.2017.64.2.173.
- Aly, T., Sanjayan, J.G. and Collins, F. (2008), "Effect of polypropylene fibers on shrinkage and cracking of concretes", Mater. Struct., 41(10), 1741. https://doi.org/10.1617/s11527-008-9361-2. https://doi.org/10.1617/s11527-008-9361-2
- Babafemi, A.J. and Boshoff, W.P. (2016), "Testing and modelling the creep of cracked macro-synthetic fibre reinforced concrete (msfrc) under flexural loading", Mater. Struct., 49(10), 4389-4400. https://doi.org/10.1617/s11527-016-0795-7. https://doi.org/10.1617/s11527-016-0795-7
- Bahadori-Jahromi, A., Rotimi, A., Tovi, S., Goodchild, C. and Rizzuto, J. (2017), "Evaluation of the influence of creep and shrinkage determinants on column shortening in mid-rise buildings", Adv. Concrete Constr., 5(2), 155-171. https://doi.org/10.12989/acc.2017.5.2.155. https://doi.org/10.12989/acc.2017.5.2.155
- Bazant, Z.P. (2000), "Criteria for rational prediction of creep and shrinkage of concrete", ACI Spec. Pub., 194, 237-260.
- Bazant, Z.P. and Baweja, S. (1996), "Creep and shrinkage prediction model for analysis and design of concrete structuresmodel b3", Mater. Struct., 29(2), 126-126. https://doi.org/10.1007/BF02486204
- Branson, D.E. (1977), Deformation of Concrete Structures, McGraw-Hill.
- CEB-FIP (1970), International Recommendations for the Design and Construction of Concrete Structures, Cement and Concrete Association, London.
- Chen, C., Wang, Z.L., Gao, Q.F. and Wei-Zhao, L.I. (2015), "Mid-span deflection analysis of the long-span prestressed concrete continuous box-girder bridge based on the stiffness decreasing", Science Technology & Engineering.
- Di, H.U. (2006), "The steel restraint influence coefficient method to analyze time-dependent effect in prestressed concrete bridges", Eng. Mech., 6.
- Gardner, N.J. and Lockman, M.J. (2002), "Design provisions for drying shrinkage and creep of normal-strength concrete", ACI Mater. J., 98(2), 159-167.
- Gilbert, R.I. (1988), Time Effects in Concrete Structures, Elsevier.
- Gilbert, R.I. (1999), "Deflection calculations for reinforced concrete structures-why we sometimes get it wrong", ACI Struct. J., 96(6), 1027-1032.
- Giordano, L., Recupero, A. andTondolo, F. (2008), "Serviceability behaviour of pc structures by probabilistic and fuzzy probabilistic approaches", Struct. Infrastr. Eng., 4(2), 153-162. https://doi.org/10.1080/15732470601155565. https://doi.org/10.1080/15732470601155565
- Gosaye, J., Gardner, L., Wadee, M.A. and Ellen, M.E. (2014), "Tensile performance of prestressed steel elements", Eng. Struct., 79, 234-243. https://doi.org/10.1016/j.engstruct.2014.08.009. https://doi.org/10.1016/j.engstruct.2014.08.009
- Huo, X. (1997), "Time-dependent analysis and application of high-performance concrete in bridges".
- JTG D62-2004 (2004), Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts, Ministry of Communications of China, Beijing. (in Chinese)
- Kok-Seng Chia, Xuemei Liu, Jat-Yuen Richard Liew. et.al. (2014), "Experimental study on creep and shrinkage of highperformance ultra lightweight cement composite of 60 MPa", Struct. Eng. Mech., 50(5), 635-652. https://doi.org/10.12989/sem.2014.50.5.635. https://doi.org/10.12989/sem.2014.50.5.635
- Mari, A.R., Bairan, J.M. and Duarte, N. (2010), "Long-term deflections in cracked reinforced concrete flexural members", Eng. Struct., 32(3), 829-842. https://doi.org/10.1016/j.engstruct.2009.12.009. https://doi.org/10.1016/j.engstruct.2009.12.009
- Neville, A.M. and Dilger, W.H. (1970), Creep of Concrete: Plain, Reinforced, and Prestressed, North-Holland Pub. Co.
- Padron, I. and Zollo, R.F. (1990), "Effect of synthetic fibers on volume stability and cracking of portland cement concrete and mortar", ACI Mater. J., 87(4), 327-332.
- Pan, Z. and Meng, S. (2016), "Three-level experimental approach for creep and shrinkage of high-strength high-performance concrete", Eng. Struct., 120, 23-36. https://doi.org/10.1016/j.engstruct.2016.04.009. https://doi.org/10.1016/j.engstruct.2016.04.009
- Pan, Z., Lu, Z. and Fu, C. C. (2011), "Experimental study on creep and shrinkage of high-strength plain concrete and reinforced concrete", Adv. Struct. Eng., 14(2), 235-248. https://doi.org/10.1260/1369-43126.96.36.199. https://doi.org/10.1260/1369-43188.8.131.52
- Podhorsky, I. and Maric, Z. (1990), "MC90 - the new CEB-FIP Model Code for Concrete Structures", Treci Kongres Drustva Gradevinskih Konstruktora Hrvatske, Hrvatska Znanstvena Bibliografija i MZOS-Svibor.
- Qi, C., Weiss, J. and Olek, J. (2003), "Characterization of plastic shrinkage cracking in fiber reinforced concrete using image analysis and a modified weibull function", Mater. Struct., 36(6), 386-395. https://doi.org/10.1007/BF02481064. https://doi.org/10.1007/BF02481064
- Sun, B. (1992), "Time dependent prestress losses and time effects in modern prestressed concrete structures", PhD Thesis, Southeast University, Nanjing, China. (in Chinese)
- Tadros, M.K., Ghali, A. and Dilger, W.H. (1977), "Effect of nonprestressed steel on prestress loss and deflection", PCI J., 22(2), 50-63.
- Weiss, W.J., Yang, W. and Shah, S.P. (1998), "Shrinkage cracking of restrained concrete slabs", J. Eng. Mech., 124(7), 765-774. https://doi.org/10.1061/(ASCE)0733-9399(1998)124:7(765). https://doi.org/10.1061/(ASCE)0733-9399(1998)124:7(765)
- Wen, Q. (2006), "Analysis of shrinkage and creep effects in widening reinforced concrete girder", J. Southeast Univ., 36(4), 596-600.
- Xiang, Y. and He, X. (2017), "Short- and long-term analyses of shear lag in RC box girders considering axial equilibrium", Struct. Eng. Mech., 62(6), 725-737. https://doi.org/10.12989/sem.2017.62.6.725.
- Xie, C. (2009), "Experimental study on creep deformation of longspan bridge with ballastless track", Science & Technology of West China.
- Xu, J. (2008), "Experimental and theoretical study on creep and shrinkage effects in continuous concrete bridges", Master's Thesis, Department of Bridge and Tunnel Engineering, Chongqing Jiaotong University, Chongqing, China. (in Chinese)
- Zou, D., Liu, T., Teng, J., Du, C. and Li, B. (2014), "Influence of creep and drying shrinkage of reinforced concrete shear walls on the axial shortening of high-rise buildings", Constr. Build. Mater., 55(2), 46-56. https://doi.org/10.1016/j.conbuildmat.2014.01.034. https://doi.org/10.1016/j.conbuildmat.2014.01.034
Supported by : National Natural Scientific Fund, Beijing Municipal Education Commission, Beijing University of Civil Engineering and Architecture