One-Way Slab Design Limits per ACI 318-19 with ideCAD

How does ideCAD control one-way slab design limits according to ACI 318-19?


  • The minimum slab thickness is controlled and reported automatically according to Table 7.3.1.1.

  • For nonprestressed slabs not satisfying 7.3.1, immediate and time-dependent deflection is calculated according to 24.2 and is not exceed the limits in 24.2.

  • Slab thickness is detemined by user.


Symbols

h = overall thickness, height, or depth of member, in.
l = span length of beam or one-way slab; clear projection of cantilever, in.
fy = specified yield strength for nonprestressed reinforcement, psi


Design limits

Minimum Slab thickness

The minimum slab thickness is controlled automatically according to Table 7.3.1.1. If calculated deflection limits of 7.3.2 are satisfied, the minimum slab thickness condition is not controlled.

Support Condition

Minimum slab thickness, h

Support Condition

Minimum slab thickness, h

Simply supported

l/20

One end continuous

l/24

Both ends continuous

l/28

Cantilever

l/10

For fy other than 60,000 psi, the expressions in Table 7.3.1.1 are multiplied by (0.4 + fy/100,000).

Calculated deflection limits

For nonprestressed slabs not satisfying 7.3.1, immediate and time-dependent deflection is calculated according to 24.2 and does not exceed the limits in 24.2.2.

Reinforcement strain limit in nonprestressed slabs

It’s automatically designed according to Strength Reduction Factors per ACI 318-19 with ideCAD.