Title:
Concentric Punching Shear of Waffle Slab
Author(s):
Ahmed Faleh Al-Bayati, Teck Leong Lau, and Leslie A. Clark
Publication:
Structural Journal
Volume:
112
Issue:
5
Appears on pages(s):
533-542
Keywords:
design; internal column; plasticity; punching shear; reinforced concrete, waffle slab.
DOI:
10.14359/51687906
Date:
9/1/2015
Abstract:
This paper presents test results of fifteen 1/10th-scale microconcrete waffle slabs subjected to concentric punching shear. Although the observed punching failure mechanism of waffle slabs was found to be very similar to that of flat slabs, the shear capacity is relatively reduced because some of the potential failure surface is lost when it extends into the waffle section. Because the current codes of practice do not consider the punching shear mechanism of waffle slabs, the comparisons with the test results revealed that BS8110 and EC2 overestimated the punching capacities of waffle slabs, whereas ACI’s prediction was conservative. A prediction model based on the upper-bound plasticity theory was proposed to predict the failure loads, which gave good agreements with the tests.
Related References:
1. Magura, D. D., and Corley, W. G., “Tests to Destruction of a Multi Panel Waffle Slab Structure 1964-1965 New York World’s Fair,” ACI Journal Proceedings, V. 69, No. 9, Sept. 1971, pp. 699-703.
2. Xiang, X. Z., “Punching Shear Strength of Waffle Slabs at Internal Columns,” PhD dissertation, University of Leeds, Leeds, UK, 1993, 236 pp.
3. Hussein, A. F., “Punching Shear Strength at Edge Columns in Ribbed Flat Slabs,” PhD dissertation, University of Leeds, Leeds, UK, 1994, 266 pp.
4. Mosalam, K. M., and Naito, C. J., “Seismic Evaluation of Gravity-Load-Designed Column-Grid System,” Journal of Structural Engineering, ASCE, V. 128, No. 2, 2002, pp. 160-168. doi: 10.1061/(ASCE)0733-9445(2002)128:2(160)
5. Benavent-Climent, A.; Cahís, X.; and Catalan, A., “Seismic Behaviour of Interior Connections in Existing Waffle-Flat-Plate Structures,” Engineering Structures, V. 30, No. 9, 2008, pp. 2510-2516. doi: 10.1016/j.engstruct.2008.02.004
6. Souza, S. S. M., and Oliveira, D. R. C., “Reinforced Concrete Waffle Flat Slabs under Shearing,” IBRACON Structures and Materials Journal, V. 4, No. 4, 2011, pp. 610-625.
7. ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 519 pp.
8. EN 1992-1-1, “Eurocode 2—Design of Concrete Structures – Part 1: General Rules and Rules for Buildings,” European Committee for Standardization, Brussels, Belgium, 2004, 225 pp.
9. BS8110-1:1997, “Structural Use of Concrete—Part 1: Code of Practice for Design and Construction,” British Standards Institution, London, UK, 1997, 120 pp.
10. Clark, L. A., and Lau, T. L., “Shear Transfer between Ribbed Slab and Internal Column,” Magazine of Concrete Research, V. 59, No. 7, Sept. 2007, pp. 507-516. doi: 10.1680/macr.2007.59.7.507
11. Johnson, R. P., “Strength Tests on Scaled-Down Concrete Suitable for Models with a Note on Mix Design,” Magazine of Concrete Research, V. 14, No. 40, Mar. 1962, pp. 47-53. doi: 10.1680/macr.1962.14.40.47
12. Kani, G. N. J., “How Safe Are Our Large Concrete Beams?” ACI Journal Proceedings, V. 64, No. 3, Mar. 1967, pp. 128-141.
13. Bažant, Z. P., and Kazemi, M. T., “Size Effect on Diagonal Shear Failure of Beams without Stirrups,” ACI Structural Journal, V. 88, No. 3, May-June 1991, pp. 268-276.
14. Regan, P. E., and Braestrup, M. W., “Punching Shear in Reinforced Concrete: A State-of-the-Art Report,” Bulletin d’Information No. 168, Comité Euro-International du Béton (CEB), Lausanne, Switzerland, 1985, 232 pp.
15. Sherwood, E. G.; Bentz, E. C.; and Collins, M. P., “Effect of Aggregate Size on Beam-Shear Strength of Thick Slabs,” ACI Structural Journal, V. 104, No. 2, Mar.-Apr. 2007, pp. 180-190.
16. Boswell, L. F., and Wong, S. S., “The Shear Behaviour of Micro-Concrete and Its Inclusion in a Proposed Yield Criterion,” Proceedings of Cement and Concrete Association Research Seminar, Wexham Springs, 1981, pp. 217-227.
17. Wong, S. S., “Collapse Behaviour of Micro-Concrete Box Girders Bridges,” PhD thesis, City University London, London, UK, 1998, pp. 33-46.
18. Mattock, A. H.; Ibrahim, I. O.; and Hofbeck, J. A., “Shear Transfer in Reinforced Concrete,” ACI Journal Proceedings, V. 66, No. 2, Feb. 1969, pp. 119-128.
19. Gonnerman, H. F., “Effect of Size and Shape of Test Specimen on Compressive Strength of Concrete,” Proceedings ASTM, 1925, 25 Part II, pp. 237-250.
20. Harris, H. G.; Sabnis, G. M.; and White, R. N., “Small Scale Direct Model of Reinforced and Prestressed Concrete Structures,” Report No. 326, Department of Civil Engineering, Cornell University, Ithaca, NY, 1966, 362 pp.
21. Harris, H. G., and Sabins, G. M., Structural Modeling and Experimental Techniques, second edition, CRC Press, LLC, Boca Raton, FL, 1999, 785 pp.
22. Endersbee, L. A., “Discussion of ‘Size Effects in Small-Scale Models,’” ACI Journal, Proceedings, V. 63, No. 11, Oct. 1966, pp. 1572-1573.
23. Clark, L. A., “Crack Similitude in 1:3:7 Scale Models of Slabs Spanning One Way,” Technical Report, Cement and Concrete Association, London, UK, Mar. 1971.
24. Criswell, M. E., “Static and Dynamic Response of Reinforced Concrete Slab-Column Connections,” Shear in Reinforced Concrete, SP-42, V. 2, eds., American Concrete Institute, Farmington Hills, MI, 1974, pp. 721-746.
25. Regan, P. E., “Behaviour of Reinforced Concrete Flat Slabs,” CIRIA Report 89, Construction Industry Research and Information Association, London, UK, 1981, 89 pp.
26. Schnellenbach-Held, M., and Pfeffer, K., “Punching Behaviour of Biaxial Hollow Slabs,” Cement and Concrete Composites, V. 24, No. 6, 12 2002, pp. 551-556. doi: 10.1016/S0958-9465(01)00071-3
27. Marzouk, H., and Hussein, A., “Experimental Investigation on the Behavior of High-Strength Concrete Slabs,” ACI Structural Journal, V. 88, No. 6, Nov.-Dec. 1991, pp. 701-713.
28. Braestrup, M. W.; Nielsen, M. P.; Jensen, B. C.; and Bach, F., 1976, “Axisymmetric Punching and Reinforced Concrete,” Report No. R-75, Structural Research Laboratory, Technical University of Denmark, Kongens Lyngby, Denmark, 33 pp.
29. Salim, W., and Sebastian, W. M., “Plasticity Model for Predicting Punching Shear Strengths of Reinforced Concrete Slabs,” ACI Structural Journal, V. 99, No. 6, Nov.-Dec. 2002, pp. 827-835.
30. Nielsen, M. P.; Braestrup, M. W.; Jensen, B. C.; and Bach, F., “Concrete Plasticity-Beam Shear-Shear in Joints-Punching Shear,” Special Publication, Danish Society for Structural Science and Engineering, Structural Research Laboratory, Technical University of Denmark, Lyngby, Denmark, 1978, 129 pp.
31. Nielsen, M. P., and Hoang, L. C., Limit Analysis and Concrete Plasticity, third edition, CRC Press, Boca Raton, FL, 2011, 799 pp.
32. Sigurdsson, T. G., “Punching Shear by Eccentric Loading,” MSc dissertation, Technical University of Denmark, Kongens, Lyngby, Denmark, 1991.(in Danish)
33. Moe, J., “Shearing Strength of Reinforced Concrete Slabs and Footings under Concentrated Loads,” Bulletin No. D47, Journal of the Portland Cement Association, Research and Development Laboratories, Apr. 1961, 130 pp.
34. Mowrer, R., and Vanderbilt, M., “Shear Strength of Lightweight Aggregate Reinforced Concrete Flat Plates,” ACI Journal Proceedings, V. 64, No. 11, Nov. 1967, pp. 722-729.
35. Regan, P. E., “Symmetric Punching of Reinforced Concrete Slabs,” Magazine of Concrete Research, V. 38, No. 136, 1986, pp. 115-128. doi: 10.1680/macr.1986.38.136.115
36. Gardner, N. J., “Relationship of the Punching Shear Capacity of Reinforced Concrete Slabs with Concrete Strength,” ACI Structural Journal, V. 87, No. 1, Jan.-Feb. 1990, pp. 66-71.
37. Tomaszewicz, A., “High-Strength Concrete: SP2-Plates and Shells—Report 2.3,” Punching Shear Capacity of Reinforced Concrete Slabs, Report No. STE70 A93082, SINTEF Structures and Concrete, Trondheim, Norway, 1993, 36 pp.
38. Hallgren, M., “Punching Shear Capacity of Reinforced High Strength Concrete Slabs,” doctoral thesis, Royal Institute of Technology, Stockholm, Sweden, 1996, 206 pp.
39. Muttoni, A., “Punching Shear Strength of Reinforced Concrete Slabs without Transverse Reinforcement,” ACI Structural Journal, V. 105, No. 4, July-Aug. 2008, pp. 67-71.
40. Guandalini, S.; Burdet, O. L.; and Muttoni, A., “Punching Tests of Slabs with Low Reinforcement Ratio,” ACI Structural Journal, V. 106, No. 1, Jan.-Feb. 2009, pp. 87-95.
41. Elshafey, A. A.; Rizk, E.; Marzouk, H.; and Haddara, M. R., “Predication of Punching Shear Strength of Two-Way Slabs,” Engineering Structures, V. 33, No. 5, 2011, pp. 1742-1753. doi: 10.1016/j.engstruct.2011.02.013