What is the term for the shear around columns in a slab?

What is the term for the shear around columns in a slab?

• A. Punching shear
• B. Diagonal shear
• C. Shear pocket
• D. Torsional shear

Answer: (A)

Punching shear describes the localized shear around a column in a slab. When a column loads a flat slab, the surrounding slab must transfer that vertical load by shear to the column. If the slab’s capacity to resist this shear within a critical zone around the column is exceeded, a cone- or pyramid-like failure can occur, effectively “punching” through the slab around the column. This is the standard term used for that failure mode around columns in slabs. Diagonal shear is a different mode typically associated with beams under shear, where cracks form along a diagonal plane. The term shear pocket isn’t a common descriptor for column-around-slab behavior, and torsional shear relates to twisting effects, not the local punching around columns.

Punching shear describes the localized shear around a column in a slab. When a column loads a flat slab, the surrounding slab must transfer that vertical load by shear to the column. If the slab’s capacity to resist this shear within a critical zone around the column is exceeded, a cone- or pyramid-like failure can occur, effectively “punching” through the slab around the column. This is the standard term used for that failure mode around columns in slabs.

Diagonal shear is a different mode typically associated with beams under shear, where cracks form along a diagonal plane. The term shear pocket isn’t a common descriptor for column-around-slab behavior, and torsional shear relates to twisting effects, not the local punching around columns.