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Two-Way Slab Design Limits.

The minimum slab thickness is controlled and reported automatically according to Codes for flat slabs.

The minimum slab thickness is controlled and reported automatically according to Codes for beam-to-slabs.


International Design Codes

ACI 318-19 : Two-Way Slab Design Limits per ACI 318-19 with ideCAD

TSC 2018 : Punching Shear Stress at Critical Section (7.11.8)


Symbols in ACI 318-19

h = overall thickness, height, or depth of member, in.
ln = length of clear span measured face-to-face of supports, in.
fy = specified yield strength for nonprestressed reinforcement, psi
αfm = average value of αf for all beams on edges of a panel


Minimum slab thickness

There are two different slab thickness limits according to flat slab and beam-to-slab.

Flat slab thickness limit

Beam-to-slab thickness limit

Calculated deflection limits


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