Title:
Maximum Shear Strength Limits for Reinforced Concrete Walls
Author(s):
Jung-Yoon Lee and Min Jae Kang
Publication:
Structural Journal
Volume:
122
Issue:
4
Appears on pages(s):
173-188
Keywords:
maximum shear strength limit; over-reinforcement; reinforced concrete (RC) walls; shear failure
DOI:
10.14359/51745490
Date:
7/1/2025
Abstract:
Reinforced concrete (RC) structure design codes stipulate various
design limits to prevent the brittle failure of members, as well as
ensure serviceability. In the structural design of RC walls, the
maximum shear strength is limited to prevent sudden shear failure
due to concrete crushing before the yielding of shear reinforcement
due to over-reinforcement. Despite the increase in wall shear
strength provided by a compression strut, the maximum shear
strength limit for walls in the ACI 318-19 Code is the same as the
maximum torsional strength. Consequently, the shear strength
of large-sized walls with high-strength concrete is limited to an
excessively low level. The ACI 318-19, Eurocode 2, CSA-19, and
JSCE-17 standards provide similar equations for estimating wall
strength, but their maximum shear strength limits for walls are all
different. In this study, experimental tests were conducted on nine
RC wall specimens to evaluate the maximum shear strength. The
main variables of the specimens were shear reinforcement ratio,
compressive strength of concrete, and failure mode. The experimental results showed that the maximum load was reached after yielding of shear reinforcement, even when the shear reinforcement ratio was 1.5 times higher than the maximum shear reinforcement ratio specified in the ACI 318-19 code. In addition, the measured shear crack width of all specimens at the service load level was less than 0.42 mm (0.017 in.). The shear strength limits for walls
in the current codes were compared using 109 experimental results
failing in shear before flexural yielding or shear friction failure,
assembled from the literature. The comparison indicated that the
ACI 318-19 Code limit underestimates the maximum shear strength
of walls, and it particularly underestimates the maximum shear
strength of walls with high-strength concrete or barbell-shaped
cross sections. Additionally, this study proposes an equation for
estimating the maximum shear strength limit of walls based on the
truss model. The proposed equation predicted the maximum shear
strength of RC walls with reasonable accuracy.
Related References:
1. ACI Committee 318, “Building Code Requirements For Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19) (Reapproved 2022),” American Concrete Institute, Farmington Hills, MI, 2019, 624 pp.
2. Proestos, G. T.; Bentz, E. C.; and Collins, M. P., “Maximum Shear Capacity of Reinforced Concrete Members,” ACI Structural Journal, V. 115, No. 5, Sept. 2018, pp. 1463-1473. doi: 10.14359/51702252
3. Hwang, S.-J.; Yang, Y.-H.; and Li, Y.-A., “Maximum Shear Strength of Reinforced Concrete Deep Beams,” ACI Structural Journal, V. 118, No. 6, Nov. 2021, pp. 155-164.
4. Hwang, S.-J., and Lee, H.-J., “Strength Prediction for Discontinuity Regions by Softened Strut-and-Tie Model,” Journal of Structural Engineering, ASCE, V. 128, No. 12, 2002, pp. 1519-1526. doi: 10.1061/(ASCE)0733-9445(2002)128:12(1519)
5. Lee, J.-Y.; Haroon, M.; Shin, D. I.; and Kim, S.-W., “Shear and Torsional Design of Reinforced Concrete Members with High-Strength Reinforcement,” Journal of Structural Engineering, ASCE, V. 147, No. 2, 2021, p. 04020327. doi: 10.1061/(ASCE)ST.1943-541X.0002887
6. Comite European De Normalisation (CEN), Eurocode 2: Design of Concrete Structures, Part 1-1 General Rules and Rules for Buildings (BS EN 1992-1-1), Lausanne, Switzerland, 2004.
7. CSA A23.3-19, “Design of Concrete Structures for Buildings,” CSA Group, Toronto, ON, Canada, 2019.
8. ASCE/SEI 43-05, “Seismic Design Criteria for Structures, Systems and Components in Nuclear Facilities,” American Society of Civil Engineers, Reston, VA, 2005, 96 pp.
9. JSCE, Standard Specifications for Concrete Structures, Japan Society of Civil Engineering, Japan, 2017.
10. Nielsen, M. P.; Braestrup, M. W.; Jensen, B. C.; and Bach, F., Concrete Plasticity, Danish Society for Structural and Engineering, 1978.
11. Vecchio, F., and Collins, M. P., “The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear,” ACI Structural Journal, V. 83, No. 2, Mar.-Apr. 1986, pp. 219-231.
12. Baek, J.-W.; Park, H.-G.; Lee, J.-H.; and Bang, C.-J., “Cyclic Loading Test for Walls of Aspect Ratio 1.0 and 0.5 with Grade 550 MPa (80 ksi) Shear Reinforcing Bars,” ACI Structural Journal, V. 114, No. 4, July-Aug. 2017, pp. 969-982. doi: 10.14359/51689680
13. Kabeyasawa, T., and Matsumoto, K., “Tests and Analysis of Ultra-High Strength Reinforced Concrete Shear Walls,” 10th World Conference on Earthquake Engineering, Rotterdam, the Netherlands, 1992, pp. 3291-3297.
14. Luna, B. N.; Rivera, J.; Epackachi, S.; and Whittaker, A. S., “Seismic Response of Low Aspect Ratio Reinforced Concrete Walls,” Technical Report MCEER-18-0002, University at Buffalo, State University of New York, Buffalo, NY, 2019, 415 pp.
15. Luna, B. N., and Whittaker, A. S., “Peak Strength of Shear-Critical Reinforced Concrete Walls,” ACI Structural Journal, V. 116, No. 2, Mar. 2019, pp. 257-266. doi: 10.14359/51712280
16. Moscoso, J. F.; Hube, M. A.; and María, H. S., “Residual Seismic Capacity of Reinforced Concrete Walls with Unconfined Boundaries,” ACI Structural Journal, V. 118, No. 5, Sept. 2021, pp. 205-220.
17. Eom, T.-S.; Park, H.-G.; Kim, H.-Y.; and Lee, H.-S., “Web Crushing and Deformation Capacity of Low-Rise Walls Subjected to Cyclic Loading,” ACI Structural Journal, V. 110, No. 4, July-Aug. 2013, pp. 575-584.
18. Carrillo, J., and Alcocer, S. M., “Shear Strength of Reinforced Concrete Walls for Seismic Design of Low-Rise Housing,” ACI Structural Journal, V. 110, No. 3, May-June 2013, pp. 415-459.
19. Chiou, Y. J.; Mo, Y. L.; Hsiao, F. P.; Liou, Y. W.; and Sheu, M. S., “Behavior of High Seismic Performance Walls,” 13th World Conference on Earthquake Engineering, Vancouver, BC, Canada, 2004, Paper No. 3180.
20. Gulec, C. K., and Whittaker, A. S., “Empirical Equations for Peak Shear Strength of Low Aspect Ratio Reinforced Concrete Walls,” ACI Structural Journal, V. 108, No. 1, Jan.-Feb. 2011, pp. 80-89.
21. Lee, J.-Y., and Hwang, H.-B., “Maximum Shear Reinforcement of Reinforced Concrete Beams,” ACI Structural Journal, V. 107, No. 5, Sept.-Oct. 2010, pp. 580-588.
22. ACI Committee 224, “Control of Cracking in Concrete Structures (ACI 224R-01),” American Concrete Institute, Farmington Hills, MI, 2001, 46 pp.
23. Park, R., and Paulay, T., Reinforced Concrete Structures, John Wiley & Sons, New York 1975, 769 pp.
24. Haroon, M.; Shin, D.; Lee, J.-Y.; and Kim, C., “Deformability of Reinforced Concrete Columns Failing in Shear after Flexural Reinforcement Yielding,” ACI Structural Journal, V. 117, No. 3, May 2020, pp. 71-90.
25. Park, R., “Ductility Evaluation from Laboratory and Analytical Testing,” Proceedings of the 9th World Conference on Earthquake Engineering, V. 8, Tokyo-Kyoto, Japan, 1988, pp. 605-616.
26. Moretti, M. L.; Kono, S.; and Obara, T., “On the Shear Strength of Reinforced Concrete Walls,” ACI Structural Journal, V. 117, No. 5, Sept. 2020, pp. 293-304.
27. Farvashany, F. E., “Parametric Studies on Reinforced Concrete Shear Walls: An Engineering Response to Einstein’s Riddle?” ACI Structural Journal, V. 114, No. 5, Sept.-Oct. 2017, pp. 1099-1108. doi: 10.14359/51700777
28. Hsu, T. T. C., “Softening Truss Model for Shear and Torsion,” ACI Structural Journal, V. 85, No. 6, Nov.-Dec. 1988, pp. 624-635.
29. Eibl, J., Concrete Structures Euro-Design-Handbook, 1994/96, Ernst & Sohn, Berlin, Germany, 1994, 764 pp.