Punching of concrete slabs

Research on punching shear is crucial, as it often controls the choice of the plate thickness in the design of flat slabs. Furthermore, the concequences of a punching failure are catastrophic, as demontrated by several accidents.
 
An important experimental research has been performed by the Structural Concrete Laboratory of EPFL, with more than 200 punching tests on full-size specimens since the year 2000. A mechanical model, the Critical Shear Crack Theory, has been developed. Initially applicable to symmetrical cases for slabs without transverse reinforcement, it has been expanded since and gives excellent results for all kinds of practical cases : slabs with transverse reinforcement, edge and corner columns, prestressed and post-tensioned slabs, fiber-reinforced concrete, strengthening of slabs, ...
 
Consequently, this model has been adopted by the Swiss Concrete Code SIA 262 (2003 and 2013) and by the fib 2010 Model-Code.

Theoretical model for symmetrical punching of slabs without transverse reinforcement

• Simões J. T., Fernández Ruiz M., Muttoni A., Validation of the Critical Shear Crack Theory for punching of slabs without transverse reinforcement by means of a refined mechanical model, Structural Concrete, 2018, pp. 191-216.
• Muttoni A., Fernández Ruiz M., Simões J. T., The theoretical principles of the critical shear crack theory for punching shear failures and derivation of consistent closed-form design expressions, Structural concrete, 2017, pp. 1-17.
• Muttoni A., Punching shear strength of reinforced concrete slabs without transverse reinforcement, ACI Structural Journal, Excel sheet, V. 105, N° 4, USA, 2008, pp. 440-450.

Theoretical model for symmetrical punching of slabs with transverse reinforcement

• Fernández Ruiz M., Muttoni A., Applications of the critical shear crack theory to punching of R/C slabs with transverse reinforcement, ACI Structural Journal, Vol. 106 N° 4, Farmington Hills, USA, 2009, pp. 485-494.

Experimental investigation of slabs without punching reinforcement

• Einpaul J., Fernández Ruiz M., Muttoni A., Measurements of internal cracking in punching test slabs without shear reinforcement, Magazine of Concrete Research, 2017, 13 p.
• Guandalini S., Burdet O., Muttoni A., Punching tests of slabs with low reinforcement ratios, ACI Structural Journal, V. 106, N°1, USA, 2009, pp. 87-95.

Experimental investigation of slabs with punching reinforcement

• Einpaul J., Brantschen F., Fernández Ruiz M., Muttoni A., Performance of punching shear reinforcement under gravity loading: Influence of type and detailing, ACI Structural Journal, Vol. 113, No 4, Farmington Hills, USA, 2016, pp. 827-838.
• Lips S., Fernández Ruiz M., Muttoni A., Experimental Investigation on Punching Strength and Deformation Capacity of Shear-Reinforced Slabs, ACI Structural Journal, Vol. 109, USA, 2012, pp. 889-900.

Size effect

• Fernández Ruiz M., Muttoni A., Size effect in shear and punching shear failures of concrete members without transverse reinforcement: Differences between statically determinate members and redundant structures, Structural concrete, 2017, pp. 1-11.

Strengthening methods of slabs against punching

• Fernández Ruiz M., Muttoni A., Kunz J., Strengthening of flat slabs against punching shear using post-installed shear reinforcement, ACI Structural Journal, V. 107 N° 4, USA, 2010, pp. 434-442.
• Faria D. M. V., Einpaul J., Ramos A.P., Fernández Ruiz M., Muttoni A., On the efficiency of flat slabs strengthening against punching using externally bonded fibre reinforced polymers, Construction and Building Materials, Vol. 73, Netherlands, 2014, pp. 366-377.

Nonsymmetrical punching

• Sagaseta J., Muttoni A., Fernández Ruiz M., Tassinari L., Non-axis-symmetrical punching shear around internal columns of RC slabs without transverse reinforcement, Magazine of Concrete Research, Vol. 63 No. 6, UK, 2011, pp. 441-457.
• Sagaseta J., Tassinari L., Fernández Ruiz M., Muttoni A., Punching of flat slabs supported on rectangular columns, Engineering Structures, 77, 2014, pp. 17-33.

Punching by seismic action

• Drakatos I.-S., Muttoni A., Beyer K., Mechanical Model for Drift-Induced Punching of Slab- Column Connections without Transverse Reinforcement, ACI Structural Journal, V. 115 No. 2, Farmington Hills, USA, 2018, pp. 463-474.
• Drakatos I.-S., Muttoni A., Beyer K., Internal slab-column connections under monotonic and cyclic imposed rotations, Engineering Structures, 123, 2016, pp. 501-516.

Influence of column size and slab slenderness

• Einpaul J., Bujnak J., Fernández Ruiz M., Muttoni A., Study on Influence of Column Size and Slab Slenderness on Punching Strength, ACI Structural Journal, V. 113, Farmington Hills, USA, 2016, pp. 135-145.

Punching of fiber-reinforced concrete slabs

• Maya Duque L. F., Fernández Ruiz M., Muttoni A., Foster S. J., Punching shear strength of steel fibre reinforced concrete slabs, Engineering Structures, Vol. 40, UK, 2012, pp. 93-94.

Punching of prestressed concrete slabs

• Clément T., Ramos A.P., Fernández Ruiz M., Muttoni A., Influence of prestressing on the punching strength of post-tensioned slabs, Engineering structures, 2014, pp. 59-69.
• Clément T., Ramos A.P., Fernández Ruiz M., Muttoni A., Design for punching of prestressed concrete slabs, Structural Concrete, Vol. 14, No. 2, Lausanne, Switzerland, 2013, pp. 157-167.

Punching of continuous slabs

• Belletti B., Muttoni A., Ravasini S., Vecchi F., Parametric analysis on punching shear resistance of reinforced-concrete continuous slabs, Magazine of Concrete Research, 2018, 14 p.
• Einpaul J., Ospina C. E., Fernández Ruiz M., Muttoni A., Punching shear capacity of continuous slabs, ACI Structural Journal, Farmington Hills, USA, 2016, pp. 861-872.
• Einpaul J., Fernández Ruiz M., Muttoni A., Influence of moment redistribution and compressive membrane action on punching strength of flat slabs, Engineering structures, Vol. 86, UK, 2015, pp. 43-57.

Punching of footings

• Simões J. T., Faria D. M. V., Fernández Ruiz M., Muttoni A., Strength of reinforced concrete footings without transverse reinforcement according to limit analysis, Engineering structures, Vol. 112, UK, 2016, pp. 146-161.
• Simões J. T., Bujnak J., Fernández Ruiz M., Muttoni A., Punching shear tests on compact footings with uniform soil pressure, Structural Concrete, n° 4, Suisse, 2016, pp. 603-617.

Punching and slab-column connections subjected to very high column loads

• Guidotti R., Fernández Ruiz M., Muttoni A., Crushing and Flexural Strength of Slab-Column Joints, Engineering structures, Vol. 33 n° 3, 2011, pp. 855-867 .
• Guidotti R., Fernández Ruiz M., Muttoni A., Durchstanzen von Flachdecken bei hohen Stützenlasten, Beton- und Stahlbetonbau, 105, Berlin, Germany, 2010, 19-26.

Slabs with concentrated loads in the vicinity of linear supports

• Natário F., Fernández Ruiz M., Muttoni A., Shear strength of RC slabs under concentrated loads near clamped linear supports, Engineering structures, 76 (2014), 2014, pp. 10-23.
• Vaz Rodrigues R., Fernández Ruiz M., Muttoni A., Shear strength of R/C bridge cantilever slabs, Engineering structures, Vol. 30, Netherlands, 2008, pp. 3024-3033.

Punching due to impact loading

• Micallef K., Sagaseta J., Fernández Ruiz M., Muttoni A., Assessing punching shear failure in reinforced concrete flat slabs subjected to localised impact loading, International Journal of Impact Engineering, Vol. 71, 2014, pp. 17-33.

Codes

• Muttoni A., Fernández Ruiz M., Bentz E. C., Foster S. J., Sigrist V., Background to the Model Code 2010 Shear Provisions - Part II Punching Shear, Structural Concrete, Ernst & Sohn, Vol.14, No. 3, Berlin, Germany, 2013, pp. 195-203.