Nonprestressed two-way joist systems (Waffle Slabs) (v12)
Minimum slab thickness over fillers is controlled and reported automatically.
If the minimum slab thickness condition is not provided, the programme gives warnings.
Minimum width of ribs condition is controlled and reported automatically.
Nonprestressed two-way joist systems is designed according to ACI 8.8.
Spaced ribs and a top slab are parts of waffle slabs.
Minimum width of ribs is 4 in.
Overall depth of ribs do not exceed 3.5 times the minimum width.
Clear spacing between ribs is maximum 30 in.
At least one bottom bar in each joist are continued and anchored to develop fy at the face of supports.
To provide slab moment strength requirements, considering load concentrations, reinforcement area perpendicular to the ribs is designed and is at least the shrinkage and temperature reinforcement area according to 24.4.
Joist systems with structural fillers
Minimum slab thickness over fillers is the greater of one-twelfth the clear distance between ribs and 1.5 in.
Joist systems with other fillers
Minimum slab thickness is the greater of one-twelfth the clear distance between ribs and 2 in., if fillers not complying 18.104.22.168 or removable forms are used.