Title:
Performance Comparison of Hooked Plain and Deformed Bars in Concrete
Author(s):
Bjorn E. Vors and Lisa R. Feldman
Publication:
Structural Journal
Volume:
118
Issue:
5
Appears on pages(s):
91-99
Keywords:
anchorage; beam-column joint specimen; bond and develop-ment; deformed reinforcement; hooks; plain reinforcement; reinforced concrete
DOI:
10.14359/51732864
Date:
9/1/2021
Abstract:
Ninety- and 180-degree hooked plain and deformed bars were tested in beam-column specimens. Six replicate specimens were tested for each bar type and bend angle to evaluate whether differences in the reported quantitative results were statistically significant. Statistically significant differences were identified in the maximum normalized tensile resistance between 90-degree hooked plain and deformed bars, 180-degree hooked plain and deformed bars, and 90- and 180-degree hooked deformed bars. Side and front face blowout were visually identified as the primary failure modes for specimens containing 90- and 180-degree hooked bars, respectively, with tail kickout noted as a secondary failure mode in select specimens containing 90-degree hooked bars. The influence of bearing capacity of concrete in advance of the bend region resulted in no statistically significant differences between displacements of the hooked bars at the maximum tensile resistance for the range of concrete strengths investigated in this study.
Related References:
1. Feldman, L. R., and Cairns, J., “Assessing Historical Provisions for Bond of Plain Bars,” ACI Structural Journal, V. 114, No. 2, Mar.-Apr. 2017, pp. 463-473. doi: 10.14359/51689163
2. Fabbrocino, G.; Verderame, G. M.; Manfredi, G.; and Cosenza, E., “Experimental Response and Behavioural Modelling of Anchored Smooth Bars in Existing RC Frames,” Proceedings of the International Conference on Bond in Concrete, Budapest, Hungary, 2002, pp. 111-118.
3. Abrams, D. A., “Tests of Bond between Concrete and Steel,” University of Illinois Bulletin No. 71, University of Illinois at Urbana-Champaign, Urbana, IL, 1913, 240 pp.
4. Mylrea, T. D., “Bond and Anchorage,” ACI Journal Proceedings, V. 44, No. 3, 1948, pp. 521-552.
5. Snowdon, L. C., Classifying Reinforcing Bars for Bond Strength, Building Research Establishment, Garston, UK, 1970, 37 pp.
6. Feldman, L. R., and Bartlett, F. M., “Bond Strength Variability in Pullout Specimens with Plain Reinforcement,” ACI Structural Journal, V. 102, No. 6, Nov.-Dec. 2005, pp. 860-867.
7. Feldman, L. R., and Bartlett, F. M., “Bond Stresses Along Plain Steel Reinforcing Bars in Pullout Specimens,” ACI Structural Journal, V. 104, No. 6, Nov.-Dec. 2007, pp. 685-692.
8. Feldman, L. R., and Bartlett, F. M., “Bond in Flexural Members with Plain Steel Reinforcement,” ACI Structural Journal, V. 105, No. 5, Sept.-Oct. 2008, pp. 552-560.
9. Bischoff, P. H., and Johnson, R. D., “Effects of Bond and Cracking on Serviceability Related Behaviour of Concrete Beams Reinforced with Plain (Undeformed) Reinforcing Bars,” Proceedings of the 2008 Annual Conference of the Canadian Society for Civil Engineering, Québec, QC, Canada, 2008, 8 pp.
10. Feldman, L. R.; Poudyal, U.; and Cairns, J., “Proposed Development Length Equation for Plain Bars,” ACI Structural Journal, V. 115, No. 6, Nov. 2018, pp. 1615-1623. doi: 10.14359/51702230
11. 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.
12. Hassan, M. N., and Feldman, L. R., “Behavior of Lap-Spliced Plain Steel Bars,” ACI Structural Journal, V. 109, No. 2, Mar.-Apr. 2012, pp. 235-244.
13. Chana, P. S., “A Test Method to Establish Realistic Bond Stresses,” Magazine of Concrete Research, V. 42, No. 151, 1990, pp. 83-90. doi: 10.1680/macr.1990.42.151.83
14. Cairns, J.; Du, Y.; and Law, D. W., “Residual Bond Strength of Corroded Plain Round Bars,” Magazine of Concrete Research, V. 58, No. 4, 2006, pp. 221-231. doi: 10.1680/macr.2006.58.4.221
15. Sekulovic MacLean, M., and Feldman, L. R., “Effects of Casting Position and Bar Shape on Bond of Plain Bars,” ACI Structural Journal, V. 111, No. 2, Mar.-Apr. 2014, pp. 323-330.
16. Mylrea, T. D., “The Carrying Capacity of Semicircular Hooks,” ACI Journal Proceedings, 1924, pp. 240-263.
17. Liu, A., and Park, R., “Seismic Behavior of Existing Moment Resisting Frames with Plain Round Bars Designed to Pre-1970s Codes,” 12th World Conference on Earthquake Engineering, Auckland, New Zealand, 2000, 8 pp.
18. Cleland, D. J.; Cummings, S. J.; Rankin, G. I.; Taylor, S.; and Scott, R. H., “Influence of Reinforcement Anchorage on the Bending and Shear Capacity of Bridge Decks,” Structural Engineering, V. 27, No. 16, Aug. 2001, pp. 24-31.
19. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19),” American Concrete Institute, Farmington Hills, MI, 2019, 623 pp.
20. Minor, J., and Jirsa, J. O., “Behavior of Bent Bar Anchorages,” ACI Journal Proceedings, V. 72, No. 4, Apr. 1975, pp. 141-149.
21. Marques, J. L., and Jirsa, J. O., “A Study of Hooked Bar Anchorages in Beam-Column Joints,” ACI Journal Proceedings, V. 72, No. 5, May 1975, pp. 198-209.
22. Pinc, R.; Watkins, M.; and Jirsa, J. O., “The Strength of the Hooked Bar Anchorages in Beam-Column Joints,” CESRL Report No. 77-3, Department of Civil Engineering – Structures Research Laboratory, University of Texas at Austin, Austin, TX, 1977, 67 pp.
23. Sperry, J.; Yasso, S.; Searle, N.; DeRubeis, M.; Darwin, D.; O’Reilly, M.; Matamoros, A.; Feldman, L. R.; Lepage, A.; Lequesne, R. D.; and Ajaam, A., “Conventional and High-Strength Hooked Bars—Part 1: Anchorage Tests,” ACI Structural Journal, V. 114, No. 1, Jan.-Feb. 2017, pp. 255-265. doi: 10.14359/51689457
24. Sperry, J.; Darwin, D.; O’Reilly, M.; Lequesne, R. D.; Yasso, S.; Matamoros, A.; Feldman, L. R.; and Lepage, A., “Conventional and High-Strength Hooked Bars—Part 2: Data Analysis,” ACI Structural Journal, V. 114, No. 1, Jan.-Feb. 2017, pp. 267-276. doi: 10.14359/51689457
25. Sperry, J.; Darwin, D.; O’Reilly, M.; Lepage, A.; Lequesne, R. D.; Matamoros, A.; Feldman, L. R.; Yasso, S.; Searle, N.; DeRubeis, M.; and Ajaam, A., “Conventional and High-Strength Bars—Part 3: Detailing Effects,” ACI Structural Journal, V. 115, No. 1, Jan. 2018, pp. 247-257. doi: 10.14359/51700920
26. Ajaam, A.; Yasso, S.; Darwin, D.; O’Reilly, M.; and Sperry, J., “Anchorage Strength of Closely Spaced Hooked Bars,” ACI Structural Journal, V. 115, No. 4, July 2018, pp. 1143-1152. doi: 10.14359/51702065
27. Baldwin, M. I., and Clark, L. A., “The Assessment of Reinforcing Bars with Inadequate Anchorage,” Magazine of Concrete Research, V. 47, No. 171, 1995, pp. 95-102. doi: 10.1680/macr.1995.47.171.95
28. Bashandy, T. R., “Application of Headed Bars in Concrete Members,” PhD dissertation, University of Texas at Austin, Austin, TX, 1996, 303 pp.
29. Vors, B., and Feldman, L. R., “An Initial Comparison of the Performance of Hooked Plain and Deformed Bars,” Proceedings of the 2019 Annual Conference of the Canadian Society for Civil Engineering, Laval, QC, Canada, 2019, 8 pp.
30. CAN/CSA A23.1/A23.2-19, “Concrete Materials and Concrete Construction/Test Methods and Standard Practices for Concrete,” Canadian Standards Association, Mississauga, ON, 2019, 691 pp.
31. CAN/CSA G40.20-13/G40-21-13 (R2018), “General Requirements for Rolled or Welded Structural Quality Steel/Structural Quality Steel,” Canadian Standards Association, Mississauga, ON, 2013, 120 pp.
32. ASTM A370-19e1, “Standard Test Method and Definitions for Mechanical Testing of Steel Products,” ASTM International, West Conshohocken, PA, 2019, 50 pp.
33. Rao, N. R.; Lohrmann, M.; and Tall, L., “Effects of Strain Rate on the Yield Stress of Structural Steels,” Journal of Materials, V. 1, No. 1, May 1966, pp. 241-262.
34. CSA G30.18-09 (R2019), “Carbon Steel Bars for Concrete Reinforcement,” Canadian Standards Association, Mississauga, ON, 2009, 27 pp.
35. ASTM E178-16a, “Standard Practice for Dealing with Outlying Observations,” ASTM International, West Conshohocken, PA, 2016, 11 pp.
36. CEB-FIP, “CEB-FIP Model Code (1993),” Comité Euro-Internationale due Béton (CEB), Thomas Telford Ltd., London, UK, 1993, 437 pp.