Title:
Punching Tests of Double-Hooked-End Fiber-Reinforced Concrete Slabs
Author(s):
K. Chanthabouala, S. Teng, J. Chandra, K.-H. Tan, and C. P. Ostertag
Publication:
Structural Journal
Volume:
115
Issue:
6
Appears on pages(s):
1777-1789
Keywords:
building codes; double-hooked-end fibers; fiber contents; fiber-reinforced concrete; flexural strength; high-strength concrete; punching shear strength; slabs; steel fiber-reinforced concrete
DOI:
10.14359/51706891
Date:
11/1/2018
Abstract:
Ten high-strength concrete slabs reinforced with a new type of steel fiber, double-hooked-end steel fibers, were tested under punching shear loads. The strength of the concrete fc′ varied from 80 to 100 MPa (11,600 to 14,500 psi). The fiber content Vf varied from 0 to 1.2%. Two different values of flexural reinforcement ratios ρ (= As/ bd) of 0.9% and 1.4% were chosen for this test program. The experimental results showed that the use of double-hooked-end steel fibers in concrete enhances slab performance significantly in many ways. As the fiber volume or fiber content Vf increased, the flexural stiffness of the slab throughout loading history also increased, while both the deflections and crack widths decreased considerably. At the ultimate load stage, the punching shear strength increased by up to 156% compared to non-fibrous concrete slabs. The increase in punching shear strength is significantly higher than the increase introduced by conventional single hooked-end steel fibers. The ductility of the slabs was also significantly improved. Comparisons between design methods with experimental results show that the design method from The Concrete Society’s TR-34 performs very well. Another method that was based on the yield line theory overestimates the strengths of the slabs. Model Code 2010 method also overestimates the punching shear strengths. Finally, some relevant design recommendations are given.
Related References:
1. ACI Committee 544, “Report on Design and Construction of Steel Fiber-Reinforced Concrete Elevated Slabs (ACI 544.6R-15),” American Concrete Institute, Farmington Hills, MI, 2015, 38 pp.
2. ACI Committee 544, “Design Considerations for Steel Fiber Reinforced Concrete (ACI 544.4R-88) (Reapproved 2009),” American Concrete Institute, Farmington Hills, MI, 1988, 18 pp.
3. ACI Comittee 544, “Guide for Specifying, Proportioning, and Production of Fiber-Reinforced Concrete (ACI 544.3R-08),” American Concrete Institute, Farmington Hills, MI, 2008, 16 pp.
4. TR 34, Concrete Industrial Ground Floors: A Guide to Design and Construction, fourth edition, The Concrete Society, Surrey, UK, 2016, 99 pp.
5. Chandler, J., and Neal, F., “The Design of Ground-Supported Concrete Industrial Floor Slabs,” Interim Technical Note 11, Cement and Concrete Association, 1988, 16 pp.
6. Li, V. C., “Large Volume, High-Performance Applications of Fibers in Civil Engineering,” Journal of Applied Polymer Science, V. 83, No. 3, 2002, pp. 660-686. doi: 10.1002/app.2263
7. Mobasher, B., and Destree, X., “Design and Construction Aspects of Steel Fiber-Reinforced Concrete Elevated Slabs,” Fiber-Reinforced Self-Consolidating Concrete: Research and Applications, SP-274, American Concrete Institute, Farmington Hills, MI, 2010, pp. 95-108.
8. Henager, C. H., “Steel Fibrous Ductile Concrete Joint for Seismic Resistant Structures,” Reinforced Concrete Structures in Seismic Zones, SP-53, American Concrete Institute, Farmington Hills, MI, 1977, pp. 371-386.
9. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 520 pp.
10. EN 1992-1-1, “Eurocode 2: Design of Concrete Structures: Part 1-1—General Rules and Rules for Buildings,” European Committee for Standarization, Brussels, Belgium, 2004, 225 pp.
11. fib bulletin 65-66, “Model Code 2010, Final Draft,” CEB-FIP, Lausanne, Switzerland, 2012.
12. Romualdi, J. P., and Mandel, J. A., “Tensile Strength of Concrete Affected by Uniformly Distributed and Closely Spaced Short Lengths of Wire Reinforcement,” ACI Journal Proceedings, V. 61, No. 6, June 1964, pp. 657-672.
13. Swamy, R. N., and Mangat, P. S., “A Theory for the Flexural Strength of Steel Fiber Reinforced Concrete,” Cement and Concrete Research, V. 4, No. 2, 1974, pp. 313-325. doi: 10.1016/0008-8846(74)90142-2
14. Swamy, R. N., and Ali, S. A. R., “Punching Shear Behavior of Reinforced Slab-Column Connections Made with Steel Fiber Concrete,” ACI Journal Proceedings, V. 79, No. 5, Sept.-Oct. 1982, pp. 392-406.
15. Narayanan, R., and Darwish, I. Y. S., “Punching Shear Tests on Steel-Fiber Reinforced Micro-Concrete Slabs,” Magazine of Concrete Research, V. 39, No. 138, 1987, pp. 42-50. doi: 10.1680/macr.1987.39.138.42
16. Theodorakopoulos, D., and Swamy, N., “Contribution of Steel Fibers to the Strength Characteristics of Lightweight Concrete Slab-Column Connections Failing in Punching Shear,” ACI Structural Journal, V. 90, No. 4, July-Aug. 1993, pp. 342-355.
17. Alexander, S. D. B., and Simmonds, S. H., “Punching Shear Tests of Concrete Slab-Column Joints Containing Fiber Reinforcement,” ACI Structural Journal, V. 89, No. 4, July-Aug. 1992, pp. 425-432.
18. Shaaban, A. M., and Gesund, H., “Punching Shear Strength of Steel Fiber Reinforced Concrete Flat Plates,” ACI Structural Journal, V. 91, No. 4, July-Aug. 1994, pp. 406-414.
19. Harajli, M. H.; Maalouf, D.; and Khatib, H., “Effect of Fibers on the Punching Shear Strength of Slab-Column Connections,” Cement and Concrete Composites, V. 17, No. 2, 1995, pp. 161-170. doi: 10.1016/0958-9465(94)00031-S
20. Higashiyama, H.; Ota, A.; and Mizukoshi, M., “Design Equation for Punching Shear Capacity of SFRC Slabs,” International Journal of Concrete Structures and Materials, V. 5, No. 1, 2011, pp. 35-42. doi: 10.4334/IJCSM.2011.5.1.035
21. Gouveia, N. D.; Fernandes, N. A. G.; Faria, D. M. V.; Ramos, A. M. P.; and Lúcio, V. J. G., “SFRC Flat Slabs Punching Behaviour – Experimental Research,” Composites. Part B, Engineering, V. 63, 2014, pp. 161-171. doi: 10.1016/j.compositesb.2014.04.005
22. Grimaldi, A.; Meda, A.; and Rinaldi, Z., “Experimental Behaviour of Fibre Reinforced Concrete Bridge Decks Subjected to Punching Shear,” Composites. Part B, Engineering, V. 45, No. 1, 2013, pp. 811-820. doi: 10.1016/j.compositesb.2012.09.044
23. Caratelli, A.; Imperatore, S.; Meda, A.; and Rinaldi, Z., “Punching Shear Behavior of Lightweight Fiber Reinforced Concrete Slabs,” Composites. Part B, Engineering, V. 99, 2016, pp. 257-265. doi: 10.1016/j.compositesb.2016.06.045
24. RILEM, “Final Recommendation of TC 162-TDF: Test and Design Methods for Steel Fibre Reinforced Concrete,” Materials and Structures, V. 36, No. 262, 2003, pp. 560-565. doi: 10.1617/14007
25. BS EN 14651, “Test Method for Metallic Fibre Concrete—Measuring the Flexural Tensile Strength (Limit of Proportionality (LOP), Residual), British Standards Institution, London, UK, 2007.
26. Theodorakopoulos, D. D., and Swamy, R. N., “A Design Method for Punching Shear Strength of Steel Fiber Reinforced Concrete Slabs,” Innovations in Fiber-Reinforced Concrete for Value, SP-216, American Concrete Institute, Farmington Hills, MI, 2003, pp. 181-202.
27. Maya, L. F.; Fernández Ruiz, M.; Muttoni, A.; and Foster, S. J., “Punching Shear Strength of Steel Fibre Reinforced Concrete Slabs,” Engineering Structures, V. 40, 2012, pp. 83-94. doi: 10.1016/j.engstruct.2012.02.009
28. BEKAERT, Dramix 5D fibres Datasheet, https://www.bekaert.com/en/product-catalog/content/datasheets/Dramix5D.
29. Johansen, K. W., Yield-Line Theory, Cement and Concrete Association, London, UK, 1962, 181 pp.
30. Muttoni, A., “Punching Shear Strength of Reinforced Concrete Slabs without Transverse Reinforcement,” ACI Structural Journal, V. 105, No. 4, July-Aug. 2008, pp. 440-450.
31. Park, R., and Gamble, W. L., Reinforced Concrete Slabs, John Wiley & Sons, New York, 2000.
32. Teng, S.; Chanthabouala, K.; Lim, T. Y.; and Hidayat, R., “Punching Shear Strength of Slabs and Influence of Low Reinforcement Ratio,” ACI Structural Journal, V. 115, No. 1, 2018, pp. 139-150. doi: 10.14359/51701089