Title:
Vertical Punching Capacity of Reinforced Concrete Flat Plates without Shear Reinforcement
Author(s):
Srinivas Mogili, Hsiang-Yun Lin, and Shyh-Jiann Hwang
Publication:
Structural Journal
Volume:
121
Issue:
1
Appears on pages(s):
171-184
Keywords:
ACI 318; analytical model; design codes; Eurocode 2; flat plates; punching; reinforced concrete; shear strength; softened strut-and-tie (SST)
DOI:
10.14359/51739193
Date:
1/1/2024
Abstract:
Reinforced concrete flat-plate systems are widely adopted in buildings owing to ease of construction and facilitating larger clear
story heights. Flat plates are routinely designed for two-way
shear to preclude brittle punching failures. Accurate assessment
of concrete contribution to shear strength is particularly important
for flat plates in carrying out a reliable and economical design. To
address this, an efficient analytical method based on the softened
strut-and-tie model to estimate punching capacity of flat plates
without shear reinforcement under gravity loading is presented.
The proposed method can account for the influence of various
key parameters such as concrete strength, plate thickness, column
geometry, longitudinal reinforcement area, and arrangement of
tension reinforcement. The proposed method, when verified against
data from 224 specimens reported in the literature, showed reasonably good accuracy with a mean test-to-estimated capacity ratio of 1.20 and a coefficient of variation (CoV) of 0.19. In comparison, average capacity ratios using ACI 318-19 and Eurocode 2 provisions were 1.60 and 1.27 (CoV of 0.34 and 0.29), respectively.
A comprehensive discussion on the effects of key parameters on
punching behavior of flat plates without shear reinforcement is
presented, and suggestions to improve existing design provisions
are provided.
Related References:
1. Hawkins, N. M., and Mitchell, D., “Progressive Collapse of Flat Plate Structures,” ACI Journal Proceedings, V. 76, No. 7, July 1979, pp. 775-808.
2. Ma, F.; Gilbert, B. P.; Guan, H.; Lu, X.; and Li, Y., “Experimental Study on the Progressive Collapse Behaviour of RC Flat Plate Substructures Subjected to Edge-Column and Edge-Interior-Column Removal Scenarios,” Engineering Structures, V. 209, 2020, p. 110299. doi: 10.1016/j.engstruct.2020.110299
3. Sherif, A. G., and Dilger, W. H., “Tests of Full-Scale Continuous Reinforced Concrete Flat Slabs,” ACI Structural Journal, V. 97, No. 3, May 2000, pp. 455-467.
4. Cho, Y. S.; Noh, S. Y.; and Kim, H. W., “Punching Shear Reinforcing Using Studs with Steel Plates in Reinforced Concrete Flat Plates,” Magazine of Concrete Research, V. 61, No. 9, 2009, pp. 721-729. doi: 10.1680/macr.2008.61.9.721
5. Corley, W. G., and Hawkins, N. M., “Shearhead Reinforcement for Slabs,” ACI Journal Proceedings, V. 65, No. 10, Oct. 1968, pp. 811-824.
6. Yamada, T.; Nanni, A.; and Endo, K., “Punching Shear Resistance of Flat Slabs: Influence of Reinforcement Type and Ratio,” ACI Structural Journal, V. 88, No. 4, July-Aug. 1992, pp. 555-563.
7. Schmidt, P.; Kueres, D.; and Hegger, J., “Punching Shear Behavior of Reinforced Concrete Flat Slabs with a Varying Amount of Shear Reinforcement,” Structural Concrete, V. 21, No. 1, 2020, pp. 235-246. doi: 10.1002/suco.201900017
8. 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.
9. EN 1992-1-1:2004, “Eurocode 2: Design of Concrete Structures − Part 1-1 General Rules and Rules for Buildings,” European Committee for Standardization, Brussels, Belgium, 2004, 230 pp.
10. Joint ASCE-ACI Committee 426, “The Shear Strength of Reinforced Concrete Members—Slabs,” Journal of the Structural Division, ASCE, V. 100, No. 8, 1974, pp. 1543-1591. doi: 10.1061/JSDEAG.0003838
11. Vanderbilt, M. D., “Shear Strength of Continuous Plates,” Journal of the Structural Division, ASCE,V. 98, No. 5, 1972, pp. 961-973. doi: 10.1061/JSDEAG.0003248
12. Marzouk, H., and Hussein, A., “Experimental Investigation on the Behavior of High-Strength Concrete Slabs,” ACI Structural Journal, V. 88, No. 6, Nov.-Dec. 1991, pp. 701-713.
13. Rankin, G. I. B., and Long, A. E., “Predicting the Punching Strength of Conventional Slab-Column Specimens,” Proceedings - Institution of Civil Engineers, V. 82, No. 2, 1987, pp. 327-346. doi: 10.1680/iicep.1987.382
14. Regan, P. E., “Symmetric Punching of Reinforced Concrete Slabs,” Magazine of Concrete Research, V. 38, No. 136, 1986, pp. 115-128. doi: 10.1680/macr.1986.38.136.115
15. Lin, I. J.; Lin, C. J.; and Lin, S. L., “Punching Shear of Reinforced Concrete Slabs,” Journal of Chinese Institute of Civil and Hydraulic Engineering, V. 8, No. 1, 1996, pp. 75-82. (in Chinese)
16. Tomaszewicz, A., “High Strength Concrete: SP2 - Plates and Shells Report 2.3. Punching Shear Capacity of Reinforced Concrete Slabs,” Report No. STF70A93082, SINTEF, Trondheim, Norway, 1993.
17. Hallgren, M., “Punching Shear Capacity of Reinforced High Strength Concrete Slabs,” doctoral thesis, KTH Royal Institute of Technology, Stockholm, Sweden, 1996.
18. McHarg, P. J.; Cook, W. D.; and Mitchell, D., “Benefits of Concentrated Slab Reinforcement and Steel Fibers on Performance of Slab-Column Connections,” ACI Structural Journal, V. 97, No. 2, Mar.-Apr. 2000, pp. 225-234.
19. Alexander, S. D. B., and Simmonds, S. H., “Tests of Column-Flat Plate Connections,” ACI Structural Journal, V. 89, No. 5, Sept.-Oct. 1992, pp. 495-502.
20. 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.
21. Dilger, W.; Birkle, G.; and Mitchell, D., “Effect of Flexural Reinforcement on Punching Shear Resistance,” Punching Shear in Reinforced Concrete Slabs, SP-232, M. A. Polak, ed., American Concrete Institute, Farmington Hills, MI, 2005, pp. 57-74.
22. Moehle, J., Seismic Design of Reinforced Concrete Buildings, McGraw-Hill Education, New York, NY, 2015.
23. Habibi, F.; Cook, W. D.; and Mitchell, D., “Predicting Post-Punching Shear Response of Slab-Column Connections,” ACI Structural Journal, V. 111, No. 1, Jan.-Feb. 2014, pp. 123-134.
24. Ramdane, K. E., “Punching Shear of High Performance Concrete Slabs,” 4th International Symposium on Utilization of High Strength High Performance Concrete, Paris, France, 1996, pp. 1015–26.
25. Osman, M.; Marzouk, H.; and Helmy, S., “Behavior of High-Strength Lightweight Concrete Slabs under Punching Loads,” ACI Structural Journal, V. 97, No. 3, May-June 2000, pp. 492-498.
26. Hawkins, N. M.; Fallsen, H. B.; and Hinojosa, R. C., “Influence of Column Rectangularity on the Behavior of Flat Plate Structures,” Cracking, Deflection and Ultimate Load of Concrete Slab Systems, SP-30, American Concrete Institute, Farmington Hills, MI, 1971, pp. 127-146.
27. Lips, S.; Ruiz, M. F.; and Muttoni, A., “Experimental Investigation on Punching Strength and Deformation Capacity of Shear-Reinforced Slabs,” ACI Structural Journal, V. 109, No. 6, Nov.-Dec. 2012, pp. 889-900.
28. Urban, T., “Nośność na Przebicie w Aspekcie Proporcji Boków Słupa [Punching Resistance in Terms of Column Side Proportions],” Report 3, Łódź, Poland, Katedra Budownictwa Betonowego, Politechnika Łódzka, 1994, 76 pp. (in Polish)
29. Oliveira, D. R. C.; Regan, P. E.; and Melo, G. S. S. A., “Punching Resistance of RC Slabs with Rectangular Columns,” Magazine of Concrete Research, V. 56, No. 3, 2004, pp. 123-138. doi: 10.1680/macr.2004.56.3.123
30. Li, K. K. L., “Influence of Size on Punching Shear Strength of Concrete Slabs,” MS thesis, McGill University, Montreal, QC, Canada, 2000.
31. Guandalini, S.; Burdet, O. L.; and Muttoni, A., “Punching Tests of Slabs with Low Reinforcement Ratios,” ACI Structural Journal, V. 106, No. 1, Jan.-Feb. 2009, pp. 87-95.
32. Bažant, Z. P., and Sun, H.-H., “Size Effect in Diagonal Shear Failure: Influence of Aggregate Size and Stirrups,” ACI Materials Journal, V. 84, No. 4, July-Aug. 1987, pp. 259-272.
33. Bažant, Z. P., and Cao, Z., “Size Effect in Punching Shear Failure of Slabs,” ACI Structural Journal, V. 84, No. 1, Jan.-Feb. 1987, pp. 44-53.
34. Dönmez, A., and Bažant, Z. P., “Size Effect on Punching Strength of Reinforced Concrete Slabs with and without Shear Reinforcement,” ACI Structural Journal, V. 114, No. 4, July-Aug. 2017, pp. 875-886. doi: 10.14359/51689719
35. Hwang, S. J.; Tsai, R. J.; Lam, W. K.; and Moehle, J. P., “Simplification of Softened Strut-and-Tie Model for Strength Prediction of Discontinuity Regions,” ACI Structural Journal, V. 114, No. 5, Sept.-Oct. 2017, pp. 1239-1248. doi: 10.14359/51689787
36. Mogili, S.; Kuang, J. S.; and Hwang, S. J., “Predicting Shear Strength of Reinforced Concrete Knee Joints in Closing and Opening Actions,” Journal of Structural Engineering, ASCE, V. 146, No. 6, 2020, pp. 1-11. doi: 10.1061/(ASCE)ST.1943-541X.0002633
37. Mogili, S., and Hwang, S. J., “Softened Strut-and-Tie Model for Shear and Flexural Strengths of Reinforced Concrete Pile Caps,” Journal of Structural Engineering, ASCE, V. 147, No. 11, 2021, p. 04021169. doi: 10.1061/(ASCE)ST.1943-541X.0003141
38. Mogili, S.; Hwang, S. J.; and Wu, P. W., “Estimating the Punching Shear Capacity of Reinforced Concrete Pile Caps,” 17th World Conference on Earthquake Engineering, 17WCEE, Sendai, Japan, 2020, p. C002938.
39. Thurlimann, B., “Shear Strength of Reinforced and Prestressed Concrete-CEB Approach,” Concrete Design: U.S. and European Practices − ACI-CEB-PCI-FIP Symposium, SP-59, American Concrete Institute, Farmington Hills, MI, 1979, pp. 93-116.
40. Shen, W. C.; Hwang, S. J.; and Li, Y. A., “Force-Displacement Model for Shear-Critical Reinforced Concrete Columns,” ACI Structural Journal, V. 118, No. 1, Jan. 2021, pp. 241-249.
41. Li, Y. A.; Weng, P. W.; and Hwang, S. J., “Seismic Performance of Reinforced Concrete Intermediate Short Columns Failed in Shear,” ACI Structural Journal, V. 116, No. 3, May 2019, pp. 195-206. doi: 10.14359/51713309
42. 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)
43. Banthia, N.; Al-Asaly, M.; and Ma, S., “Behavior of Concrete Slabs Reinforced with Fiber-Reinforced Plastic Grid,” Journal of Materials in Civil Engineering, ASCE, V. 7, No. 4, 1995, pp. 252-257. doi: 10.1061/(ASCE)0899-1561(1995)7:4(252)
44. Chen, S. L., “Punching Shear Behavior of Slab-Column Connections Strengthen with Carbon-Reinforced-Plastic Laminates,” MS thesis, National Chiao Tung University, Hsinchu, Taiwan, 2000. (in Chinese)
45. Chen, C. C.; Giduquio, M. B.; Chang, S.-C. L.; and Cheng, M.-Y., “Punching Shear Capacity of RC Slab-CFT Column Connections,” Engineering Structures, V. 218, 2020, p. 110785.
46. Hassan, M.; Rahman, A. M. A.; and Sherif, A., “Pilot Experimental Tests on Punching Shear Strength of Flat Plates Reinforced with Stirrups Punching Shear Reinforcement,” Journal of Materials and Engineering Structures, V. 4, No. 1, 2017, pp. 3-10.
47. Liao, J. S., “Fire Resistance and Punching Shear Capacity after Fire of Reinforced Concrete Slabs,” MS thesis, National Chiao Tung University, Hsinchu, Taiwan, 2013. (in Chinese)
48. Matthys, S., and Taerwe, L., “Concrete Slabs Reinforced with FRP Grids. II: Punching Resistance,” Journal of Composites for Construction, ASCE, V. 4, No. 3, 2000, pp. 154-161. doi: 10.1061/(ASCE)1090-0268(2000)4:3(154)
49. Ospina, C. E.; Alexander, S. D. B.; and Roger Cheng, J. J., “Punching of Two-Way Concrete Slabs with Fiber-Reinforced Polymer Reinforcing Bars or Grids,” ACI Structural Journal, V. 100, No. 5, Sept.-Oct. 2003, pp. 589-598.
50. Roll, F.; Zaidi, S. T. H.; Sabnis, G.; and Chuang, K., “Shear Resistance of Perforated Reinforced Concrete Slabs,” Cracking, Deflection and Ultimate Load of Concrete Slab Systems, SP-30, American Concrete Institute, Farmington Hills, MI, 1971, pp. 77-102.
51. Sistonen, E.; Mika, L.; and Seppo, H., “Teräsbetonilaatan Lävistyskapasiteetinlaskentakaavan Geometrinen Malli [The Geometrical Model of the Calculation Formula of the Punching Shear Capacity of the Reinforced Concrete Slab],” Report No. 69, Helsinki University of Technology, Espoo, Finland, 1997, 95 pp. (in Finnish)
52. Hwang, S. J.; Yang, Y. H.; and Li, Y. A., “Maximum Shear Strength of Reinforced Concrete Beams,” ACI Structural Journal, V. 119, No. 2, Mar. 2022, pp. 19-30.
53. 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.
54. Cladera, A.; Marí, A.; Bairán, J.-M.; Oller, E.; and Ribas, C., “One-Way Shear Design Method Based on a Multi-Action Model,” Concrete International, V. 39, No. 9, Sept. 2017, pp. 40-46.