Title:
Influence of Width-to-Effective Depth Ratio on Shear Strength of Reinforced Concrete Elements without Web Reinforcement
Author(s):
Antonio Conforti, Fausto Minelli, and Giovanni A. Plizzari
Publication:
Structural Journal
Volume:
114
Issue:
4
Appears on pages(s):
995-1006
Keywords:
bar spacing-to-effective depth ratio; code predictions; shear cracking; shear failure; shear strength; width-to-effective depth ratio
DOI:
10.14359/51689681
Date:
7/1/2017
Abstract:
It is well-known that the shear strength of reinforced concrete elements without web reinforcement is affected by different factors. Among them, tensile strength of concrete, longitudinal reinforcement ratio, shear span-depth ratio, size effect, axial force, and maximum aggregate size seem to be the most important. Concerning other parameters—for example, the width-toeffective depth ratio (b/d)—there is still disagreement within the research community about its possible influence on shear bearing capacity. In this context, the present research evaluates the influence of both the b/d and bar spacing-to-effective depth ratio (s/d) on the shear strength by means of an experimental program on 17 full-scale specimens characterized by b/d ranging from 0.5 to 3.5 and an s/d from 0.24 to 0.71. Results showed that, for b/d > 1, an increase in the b/d determines a non-negligible increment in the shear strength, whereas the s/d (in the considered range) does not affect the shear bearing capacity.
Related References:
1. De Cossio, D. R., “Joint ACI-ASCE Committee 326 Discussion of Shear and Diagonal Tension,” ACI Journal Proceedings, V. 59, No. 1, Jan. 1962, pp. 1323-1332.
2. Leonhardt, F., and Walther, R., “The Stuttgard Shear Tests, 1961,” Translation No. 111, Cement and Concrete Association, London, UK, 1964, pp. 134.
3. Kani, G. N. J., “How Safe are Our Large Reinforced Concrete Beams?” ACI Journal Proceedings, V. 64, No. 3, Mar. 1967, pp. 128-141.
4. Iyengar, K. T. S. R.; Rangan, B. V.; and Paloniswamy, R., “Some Factors Affecting the Shear Strength of Reinforced Concrete Members,” Indian Concrete Journal, V. 42, Dec. 1968, pp. 499-505.
5. Regan, P. E., “Tests of the Wide-beam Shear Resistance of Concrete Slabs,” Structures Research Group, Polytechnic of Central London, London, UK, Apr. 1982.
6. Sherwood, E. G.; Lubell, A. S.; Bentz, E. C.; and Collins, M. P., “One-Way Shear Strength of Thick Slabs and Wide Beams,” ACI Structural Journal, V. 103, No. 6, Nov.-Dec. 2006, pp. 794-802.
7. Shuraim, A., “Transverse Stirrup Configurations in RC Wide Shallow Beams Supported on Narrow Columns,” Journal of Structural Engineering, ASCE, V. 138, No. 3, 2012, pp. 416-424.
8. Conforti, A.; Minelli, F.; and Plizzari, G. A., “Wide-Shallow Beams with and without Steel Fibres: A Peculiar Behaviour in Shear and Flexure,” Composites. Part B, Engineering, V. 51, Aug. 2013, pp. 282-290. doi: 10.1016/j.compositesb.2013.03.033
9. Conforti, A.; Minelli, F.; Tinini, A.; and Plizzari, G. A., “Influence of Polypropylene Fibre Reinforcement and Width-to-Effective Depth Ratio in Wide-Shallow Beams,” Engineering Structures, V. 88, Apr. 2015, pp. 12-21. doi: 10.1016/j.engstruct.2015.01.037
10. Lubell, A. S., “Shear in Wide Reinforced Concrete Members,” PhD dissertation, University of Toronto, Toronto, ON, Canada, 2006, 455 pp.
11. Lubell, A. S.; Bentz, E. C.; and Collins, M. P., “Influence of Longitudinal Reinforcement on One-Way Shear in Slabs and Wide Beams,” Journal of Structural Engineering, ASCE, V. 135, 2009, pp. 78-87.
12. Gurutzeaga, M.; Oller, E.; Ribas, C.; Cladera, A.; and Marì, A., “Influence of the Longitudinal Reinforcement on the Shear Strength of One-Way Concrete Slabs,” Materials and Structures, V. 48, No. 8, June 2014, pp. 2597-2612.
13. Angelakos, D.; Bentz, E. C.; and Collins, M. P., “Effect of Concrete Strength and Minimum Stirrups on Shear Strength of Large Members,” ACI Structural Journal, V. 98, No. 3, May-June 2001, pp. 290-300.
14. Hsiung, W., and Frantz, G. C., “An Exploratory Study of the Shear Strength of Wide Reinforced Concrete Beams with Web Reinforcement,” Research CE 83-151, Department of Civil Engineering, University of Connecticut, Mansfield, CT, 1983.
15. Eurocode 2, “Design of Concrete Structures (EN 1992-1-1-),” European Committee for Standardization, Brussels, Belgium, 2004.
16. ACI 318-14, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 519 pp.
17. fib Bulletin 65, “Model Code 2010 - Final Draft,” V. 1, 2012, 350 pp.
18. fib Bulletin 66, “Model Code 2010 - Final Draft,” V. 2, 2012, 370 pp.
19. König, G., and Fischer, J., “Model Uncertainties Concerning Design Equations for the Shear Capacity of Concrete Members without Shear Reinforcement,” CEB Bulletin, V. 224, 1995, pp. 49-100.
20. Joint ACI-ASCE Committee 326, “Shear and Diagonal Tension,” ACI Journal Proceedings, V. 59, No. 1, Jan. 1962, pp. 1-30; No. 2, Feb. 1962, pp. 277-334; No. 3, Mar. 1962, pp. 352-396.
21. Vecchio, F. J., and Collins, M. P., “The Modified Compression Field Theory for Reinforced Concrete Elements Subjected to Shear,” ACI Journal Proceedings, V. 83, No. 2, Mar.-Apr. 1986, pp. 219-231.
22. Bentz, E. C.; Vecchio, F. J.; and Collins, M. P., “The Simplified MCFT for Calculating the Shear Strength of Reinforced Concrete Elements,” ACI Structural Journal, V. 103, No. 4, July-Aug. 2006, pp. 614-624.
23. EN 15630-1, “Steel for the Reinforcement and Prestressing of Concrete - Part 1: Test Methods,” European Committee for Standardization, Brussels, Belgium, 2004.
24. EN 12350-2, “Testing Fresh Concrete – Part 2: Slump-Test,” European Committee for Standardization, Brussels, Belgium, 2009.
25. Collins, M. P., and Mitchell, D., Prestressed Concrete Structures, Response Publications, Toronto, ON, Canada, 1997.
26. Wight, J. K., and MacGregor, J. G., Reinforced Concrete: Mechanics and Design, Pearson Prentice Hall, Upper Saddle River, NJ, 2009.