Title:
Slenderness Lower Limit for Sway-Inhibited Reinforced High-Strength Concrete Beam-Columns
Author(s):
Monther B. Dwaikat and Mahmud M. S. Dwaikat
Publication:
Structural Journal
Volume:
115
Issue:
5
Appears on pages(s):
1243-1252
Keywords:
axial-moment interaction; beam-column; design guidelines; finite element modeling; high-strength concrete; second-order effect; slenderness ratio
DOI:
10.14359/51702228
Date:
9/1/2018
Abstract:
In the design of reinforced concrete (RC) beam-columns, provisions in some buildings codes and standards stipulate that if the slenderness of such members is less than a certain lower limit, the second order effect can be neglected and the member is designed based on its cross-sectional capacity. Even though such lower limits were originally based on columns made of normal-strength concrete (NSC), the lower limits are presented in these codes and standards even for columns made of higher-strength concretes (HSCs). The current study investigates the applicability of such lower limits for HSC. A nonlinear finite element model of RC columns is developed using ANSYS and validated against published test data, and is then used to construct interaction axial-moment (P-M) diagrams for slender RC columns considering both material and geometric nonlinearities. The lower slenderness limit for sway-inhibited columns is reestablished based on the finite element results and compared to the limits provided in codes and standards. Also, the elastic solution is used with essential modifications to study the trend of behavior and its results are also compared to the finite element results. The study found that the limits given in the ACI Code and Eurocode are generally conservative for NSC columns but not for HSC, especially for the case of equal end moments with single curvature. Using the finite element results, a new limit for the lower slenderness for HSC columns is proposed.
Related References:
1. European Committee for Standardization EC2, “EN 1992-1-1:2004:E – Eurocode 2: Design of Concrete Structures—Part 1-1: General Rules and Rules for Buildings,” Brussels, Belgium, 2004.
2. American Concrete Institute, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 520 pp.
3. CSA, “Design of Concrete Structures (CSA A23.3-14),” Canadian Standards Association, Mississauga, ON, Canada, 2014.
4. MacGregor, J. G.; Breen, J. E.; and Pfrang, E. O., “Design of Slender Concrete Columns,” ACI Journal Proceedings, V. 67, No. 1, Jan. 1970, pp. 6-28.
5. Wang, C.-K.; Salmon, C. G.; and Pincheira, J. A., Reinforced Concrete Design, seventh edition, John Wiley & Sons, Ltd., 2007.
6. Foster, S. J., and Attard, M. M., “Experimental Tests on Eccentrically Loaded High-Strength Concrete Columns,” ACI Structural Journal, V. 94, No. 3, May-June 1997, pp. 295-302.
7. Claeson, C., and Gylltoft, K., “Slender High-Strength Concrete Columns Subjected to Eccentric Loading,” Journal of Structural Engineering, ASCE, V. 124, No. 3, 1998, pp. 233-240. doi: 10.1061/(ASCE)0733-9445(1998)124:3(233)
8. Leite, L.; Bonet, J. L.; Pallarés, L.; Miguel, P. F.; and Fernández-Prada, M. A., “Experimental Research on High Strength Concrete Slender Columns Subjected to Compression and Uniaxial Bending with Unequal Eccentricities at the Ends,” Engineering Structures, V. 48, 2013, pp. 220-232. doi: 10.1016/j.engstruct.2012.07.039
9. Mari, A. R., and Hellesland, J., “Lower Slenderness Limits for Rectangular Reinforced Concrete Columns,” Journal of Structural Engineering, ASCE, V. 131, No. 1, 2005, pp. 85-95. doi: 10.1061/(ASCE)0733-9445(2005)131:1(85)
10. Galano, L., and Vignoli, A., “Strength and Ductility of HSC and SCC Slender Columns Subjected to Short-Term Eccentric Load,” ACI Structural Journal, V. 105, No. 3, May-June 2008, pp. 259-269.
11. Pallarés, L.; Bonet, J. L.; Miguel, P. F.; and Fernández-Prada, M. A., “Experimental Research on High Strength Concrete Slender Columns Subjected to Compression and Biaxial Bending Forces,” Engineering Structures, V. 30, No. 7, 2008, pp. 1879-1894. doi: 10.1016/j.engstruct.2007.12.005
12. International Federation for Structural Concrete (fib), “Model Code for Concrete Structures,” John Wiley & Sons, Ltd, Wiley-VCH Verlag GmbH & Co. KGaA, 2010.
13. Hellesland, J., “Mechanics and Slenderness Limits of Sway-Restricted Reinforced Concrete Columns,” Journal of Structural Engineering, ASCE, V. 134, No. 8, 2008, pp. 1300-1309. doi: 10.1061/(ASCE)0733-9445(2008)134:8(1300)
14. Majewski, T.; Bobinski, J.; and Tejchman, J., “FE Analysis of Failure Behaviour of Reinforced Concrete Columns under Eccentric Compression,” Engineering Structures, V. 30, No. 2, 2008, pp. 300-317. doi: 10.1016/j.engstruct.2007.03.024
15. ACI Committee 363, “State-of-Art Report on High-Strength Concrete (ACI 363R-84),” ACI Journal Proceedings, V. 81, No. 4, July-Aug. 1984, pp. 364-411.
16. ACI Committee 209, “Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures (ACI 209R-92),” American Concrete Institute, Farmington Hills, MI, 1992, 47 pp.
17. Branson, D. E., and Christiason, M. L., “Time Dependent Concrete Properties Related to Design—Strength and Elastic Properties, Creep and Shrinkage,” Creep, Shrinkage and Temperature Effects, SP-27, American Concrete Institute, Farmington Hills, MI, 1971, pp. 257-277.
18. ACI Committee 2009, “Guide for Modeling and Calculating Shrinkage and Creep in Hardened Concrete ACI 209.2R-08),” American Concrete Institute, Farmington Hills, MI, 2008, 44 pp.
19. Branson, D. E., and Chen, C. I., “Design Procedures for Predicting and Evaluating the Time-Dependent Deformation of Reinforced, Partially Prestressed and Fully Prestressed Structures of Different Weight Concrete,” Research Report, Civil Engineering Department, University of Iowa, Iowa City, IA, 1972.
20. Mertol, H. C.; Rizkalla, S.; Zia, P.; and Mirmiran, A., “Creep and Shrinkage Behavior of High-Strength Concrete and Minimum Reinforcement Ratio for Bridge Columns,” PCI Journal, V. 55, No. 3, 2010, pp. 138-154. doi: 10.15554/pcij.06012010.138.154
21. Monteiro, P. J. M., and Mehta, P. K., Concrete: Structure, Properties, and Materials, Prentice Hall, 1993, 548 pp.
22. Persson, B., “Poisson’s Ratio of High-Performance Concrete,” Cement and Concrete Research, V. 29, No. 10, 1999, pp. 1647-1653. doi: 10.1016/S0008-8846(99)00159-3
23. Kim, J. K., and Yang, J. K., “Buckling Behaviour of Slender High-Strength Concrete Columns,” Engineering Structures, V. 17, No. 1, 1995, pp. 39-51. doi: 10.1016/0141-0296(95)91039-4