Title:
Performance of Punching Shear Reinforcement under Gravity Loading: Influence of Type and Detailing
Author(s):
Jürgen Einpaul, Fabio Brantschen, Miguel Fernández Ruiz, and Aurelio Muttoni
Publication:
Structural Journal
Volume:
113
Issue:
4
Appears on pages(s):
827-838
Keywords:
critical shear crack theory; interior slab-column connections; punching shear; shear reinforcement
DOI:
10.14359/51688630
Date:
7/1/2016
Abstract:
The performance of 11 different shear reinforcement systems against punching of inner slab-column connections under gravity loading was compared on the basis of experiments on 12 full-scale specimens, eight of them newly reported. The slab geometry and flexural reinforcement ratio (1.5) were kept constant. The shear reinforcement systems included different layouts of double-headed studs, individual links, bent-up bars, and bonded post-installed reinforcement. All the systems were found to increase both the strength and the deformation capacity of the members but exhibited varying performances. The factors influencing the maximum punching strength of different systems, such as the layout and the anchorage conditions of the transverse reinforcement units, are described and analyzed. The mechanical model of the Critical Shear Crack Theory is used to explain the observed differences and provide design guidance. Comparisons to the codes of practice (ACI 318, Eurocode 2, and Model Code 2010) are also presented.
Related References:
1. Muttoni, A., “Punching Shear Strength of Reinforced Concrete Slabs Without Transverse Reinforcement,” ACI Structural Journal, V. 105, No. 4, July-Aug. 2008, pp. 440-450.
2. Lips, S.; Fernández Ruiz, M.; 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.
3. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 530 pp.
4. Fédération internationale du béton, “fib Model Code for Concrete Structures 2010,” Ernst & Sohn, Berlin, Germany, 2013, 434 pp.
5. EN 1992-1-1:2014, “Design of Concrete Structures—Part 1: General Rules and Rules for Buildings (Including the Amendment A1:2014),” European Committee for Standardization, Brussels, Belgium, 2004, 225 pp.
6. Beutel, R., and Hegger, J., “The Effect of Anchorage on the Effectiveness of the Shear Reinforcement in the Punching Zone,” Cement and Concrete Composites, V. 24, No. 6, 2002, pp. 539-549. doi: 10.1016/S0958-9465(01)00070-1
7. 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. 5, Sept.-Oct. 1992, pp. 555-563.
8. Pérez Caldentey, A.; Padilla, P.; Corres Peiretti, H.; and Ariñez Fernández, F., “Influence of Stirrup Detailing on Punching Shear Strength of Flat Slabs,” Engineering Structures, V. 49, 2013, pp. 855-865. doi: 10.1016/j.engstruct.2012.12.032
9. Papanikolaou, K. V.; Tegos, I. A.; and Kappos, A. J., “Punching Shear Testing of Reinforced Concrete Slabs and Design Implications,” Magazine of Concrete Research, V. 57, No. 3, 2005, pp. 167-177. doi: 10.1680/macr.2005.57.3.167
10. Broms, C. E., “Ductility of Flat Plates: Comparison of Shear Reinforcement Systems,” ACI Structural Journal, V. 104, No. 6, Nov.-Dec. 2007, pp. 703-711.
11. Oliveira, D. R.; Melo, G. S.; and Regan, P. E., “Punching Strengths of Flat Plates with Vertical or Inclined Stirrups,” ACI Structural Journal, V. 97, No. 3, May-June 2000, pp. 485-491.
12. Gomes, R. B., and Regan, P. E., “Punching Strength of Slabs Reinforced for Shear with Offcuts of Rolled Steel I-Section Beams,” Magazine of Concrete Research, V. 51, No. 2, 1999, pp. 121-129. doi: 10.1680/macr.1999.51.2.121
13. Vollum, R. L.; Abdel-Fattah, T.; Eder, M.; and Elghazouli, A., “Y., “Design of ACI-Type Punching Shear Reinforcement to Eurocode 2,” Magazine of Concrete Research, V. 62, No. 1, 2010, pp. 3-16. doi: 10.1680/macr.2008.62.1.3
14. Birkle, G., and Dilger, W. H., “Shear Strength of Slabs with Double-Headed Shear Studs in Radial and Orthogonal Layouts,” Thomas T.C. Hsu Symposium: Shear and Torsion in Concrete Structures, SP-265, American Concrete Institute, Farmington Hills, MI, 2009, pp. 499-510.
15. Feix, J.; Wörle, P.; and Gerhard, A., “Ein Neuer Ansatz zur Steigerung der Durchstanztragfähigkeit Bestehender Stahlbetonbauteile [A New Method to Enhance the Shear Punching Capacity of Existing Concrete Structures],” Der Bauingenieur, V. 87, No. 4, 2012, pp. 149-155. (in German)
16. Wörle, P., “Enhanced Shear Punching Capacity by the Use of Post Installed Concrete Screws,” Engineering Structures, V. 60, 2014, pp. 41-51. doi: 10.1016/j.engstruct.2013.12.015
17. Fernández Ruiz, M.; Muttoni, A.; and Kunz, J., “Strengthening of Flat Slabs Against Punching Shear Using Post-Installed Shear Reinforcement,” ACI Structural Journal, V. 107, No. 4, July-Aug. 2010, pp. 434-442.
18. Einpaul, J.; Bujnak, J.; Fernández Ruiz, M.; and Muttoni, A., “Study on the Influence of Column Size and Slab Slenderness on Punching Strength,” ACI Structural Journal, V. 113, No. 1, Jan.-Feb. 2016, pp. 135-146.
19. Fernández Ruiz, M., and Muttoni, A., “Applications of the Critical Shear Crack Theory to Punching of Reinforced Concrete Slabs with Transverse Reinforcement,” ACI Structural Journal, V. 106, No. 4, July-Aug. 2009, pp. 485-494.
20. Muttoni, A., and Fernández Ruiz, M., “Reinforcement element for structural concrete construction,” International patent no. WO/2010/116323 A1, publication date Oct. 14, 2010.
21. Guidotti, R.; Fernández Ruiz, M.; and Muttoni, A., “Crushing and Flexural Strength of Slab-Column Joints,” Engineering Structures, V. 33, No. 3, 2011, pp. 855-867. doi: 10.1016/j.engstruct.2010.12.007
22. Gardner, N. J., and Shao, X., “Punching Shear of Continuous Flat Reinforced Concrete Slabs,” ACI Structural Journal, V. 93, No. 2, Mar.-Apr. 1996, pp. 218-228.
23. Fernández Ruiz, M.; Mirzaei, Y.; and Muttoni, A., “Post-Punching Behavior of Flat Slabs,” ACI Structural Journal, V. 110, No. 5, Sept.-Oct. 2013, pp. 801-812.
24. Stein, T.; Ghali, A.; and Dilger, W. H., “Distinction between Punching and Flexural Failure Modes of Flat Plates,” ACI Structural Journal, V. 104, No. 3, May-June 2007, pp. 357-365.
25. Marzouk, H., and Jiang, D., “Experimental Investigation on Shear Enhancement Types for High-Strength Concrete Plates,” ACI Structural Journal, V. 94, No. 1, Jan.-Feb. 1997, pp. 49-58.
26. Seible, F.; Ghali, A.; and Dilger, W. H., “Preassembled Shear Reinforcing Units for Flat Plates,” ACI Journal Proceedings, V. 77, No. 1, Jan.-Feb. 1980, pp. 28-35.
27. Rizk, E.; Marzouk, H.; and Hussein, A., “Punching Shear of Thick Plates with and without Shear Reinforcement,” ACI Structural Journal, V. 108, No. 5, Sept.-Oct. 2011, pp. 581-591.
28. Einpaul, J.; Fernández Ruiz, M.; and Muttoni, A., “Influence of Moment Redistribution and Compressive Membrane Action on Punching Strength of Flat Slabs,” Engineering Structures, V. 86, 2015, pp. 43-57. doi: 10.1016/j.engstruct.2014.12.032