Title:
Critical Bending Strain of Reinforcing Steel and the Buckled Bar Tension Test
Author(s):
Leo Barcley and Mervyn Kowalsky
Publication:
Materials Journal
Volume:
116
Issue:
3
Appears on pages(s):
53-61
Keywords:
critical bending strain; fatigue; high-strength steel; reinforced concrete; reinforcing steel; seismic design
DOI:
10.14359/51715583
Date:
5/1/2019
Abstract:
The fracture of longitudinal reinforcing steel causes the loss of load-carrying capacity in reinforced concrete (RC) members. Results of large-scale reverse cyclic column tests have indicated that the fracture of longitudinal reinforcement is influenced by the amount of buckling experienced by the reinforcing steel. Similar behavior was observed in a material test as reinforcing bars fractured in a brittle manner when pulled in tension after buckling. Brittle fracture occurred after the bending strain from buckling exceeded the critical bending strain. A material test was developed to quantify the critical bending strain, called the buckled bar tension test. The rib radius of the reinforcing bar was found to influence the magnitude of the critical bending strain. Additionally, the results of column tests indicated that the critical bending strain of the longitudinal reinforcement affected the column displacement capacity. Finally, a relationship between axial displacement and strain from bending was developed.
Related References:
1. Barcley, L. B., “Seismic Performance of A706-80 Reinforced Concrete Columns and Critical Bending Strain of Longitudinal Reinforcement,” master’s thesis, North Carolina State University, Raleigh, NC, 2018, 193 pp.
2. Mander, J. B., “Seismic Design of Bridge Piers,” PhD thesis, University of Canterbury, Christchurch, New Zealand, 1983, 503 pp.
3. Haber, Z. B.; Saiidi, M. S.; and Sanders, D. H., “Precast Concrete-Footing Connections for Accelerated Bridge Construction in Seismic Zones,” Caltrans Report No. CA13-2290, Sacramento, CA, 2013, 546 pp.
4. Ghannoum, W. M., and Slavin, C. M., “Low-Cycle Fatigue Performance of High-Strength Steel Reinforcing Bars,” ACI Materials Journal, V. 113, No. 6, Nov.-Dec. 2016, pp. 803-814. doi: 10.14359/51689116
5. Kunnath, S. K.; Kanvinde, A.; Xiao, Y.; and Zhang, G., “Effects of Buckling and Low Cycle Fatigue on Seismic Performance of Reinforcing Bars and Mechanical Couplers for Critical Structural Members,” Caltrans Report No. CA/UCD-SESM-08-01, Sacramento, CA, 2009, 77 pp.
6. Brown, J., and Kunnath, S. K., “Low-Cycle Fatigue Failure of Reinforcing Steel Bars,” ACI Materials Journal, V. 101, No. 6, Nov.-Dec. 2004, pp. 457-466.
7. Hawileh, R. A.; Abdalla, J. A.; Oudah, F.; and Abdelrahman, K., “Low-Cycle Fatigue Life Behavior of BS 460B and BS 500B Steel Reinforcing Bars,” Fatigue & Fracture of Engineering Materials & Structures, V. 33, No. 7, 2010, pp. 397-407. doi: 10.1111/j.1460-2695.2010.01452.x
8. Restrepo-Posada, J. I., “Seismic Behaviour of Connections between Precast Concrete Elements,” PhD thesis, University of Canterbury, Christchurch, New Zealand, 1992, 412 pp.
9. Erasmus, L. A., “Strain Age Embrittlement of Reinforcing Steels,” New Zealand Engineering, V. 32, No. 8, 1977, pp. 178-183.
10. Zheng, H., and Abel, A., “Stress Concentration and Fatigue of Profiled Reinforcing Steels,” International Journal of Fatigue, V. 20, No. 10, 1998, pp. 767-773. doi: 10.1016/S0142-1123(98)00051-6
11. Barbosa, A. R.; Trejo, D.; Nielson, D.; Mazerei, V.; and Tibbits, C., “High Strength Reinforcing Steel Bars: Low–Cycle Fatigue Behavior (FHWA-OR-RD-17-09),” Oregon Department of Transportation Report No. SPR 762 – Part B, Salem, OR, 2017, 70 pp.
12. Bae, S.; Mieses, A. M.; and Bayrak, O., “Inelastic Buckling of Reinforcing Bars,” Journal of Structural Engineering, ASCE, V. 131, No. 2, 2005, pp. 314-321. doi: 10.1061/(ASCE)0733-9445(2005)131:2(314)
13. Northern Digital, Inc., “OPTOTRAK Certus HD Dynamic Measuring Machine,” Waterloo, ON, Canada, 2011, https://www.ndigital.com/msci/products/certus-hd/. (last accessed Mar. 26, 2019)
14. Goodnight, J. C.; Kowalsky, M. J.; and Nau, J. M., “The Effects of Load History and Design Variables on Performance Limit States of Circular Bridge Columns,” V. 1-3, Final Report to Alaska Department of Transportation and Public Facilities, Juneau, AK, 2015, 1258 pp.
15. Helgason, T.; Hanson, J. M.; Somes, N. F.; Corley, W. G.; and Hognestad, E., “Fatigue of High-Yield Reinforcing Bars,” National Cooperative Highway Research Program Report 164, Transportation Research Board National Research Council, Washington, DC, 103 pp.
16. Modi, A.; Hindolia, D. A.; and Sharma, R., “Sequential Improvement of Quenching-Self-Tempering-Thermal-Treatment Rolling Process for a Modern Manufacturing System – A Case Study,” International Journal of Innovations in Engineering and Technology, V. 4, No. 4, 2014, pp. 100-111.
17. Paul, S. K.; Rana, P. K.; Das, D.; Chandra, S.; and Kundu, S., “High and Low Cycle Fatigue Performance Comparison between Micro-Alloyed and TMT Rebar,” Construction and Building Materials, V. 54, 2014, pp. 170-179. doi: 10.1016/j.conbuildmat.2013.12.061