Curling Stress Calculation Example

Calculate various warping stresses for a rigid pavement slab with the following parameters and conditions:

• k = 200 pci

• DT = 3° F/in.

• e = 0.000005/°F

• m = 0.15

• E = 5,000,000 psi

• slab length = 14 ft.

• slab width = 12 ft.

• slab thickness h = 9 in.
   

1.	Calculate radius of relative stiffness.
2.	Calculate B/l values for determining C values (use Figure 2).	slab = 14 ft (168 in.);  B/l = 168/35.3 = 4.8 Þ C = 0.68
3.	Calculate maximum edge curling stress.
4.	Calculate interior curling stresses.	longitudinally, B/l = 168/35.3 = 4.8  Þ C1 = 0.68 transversely, B/l = 144/35.3 = 4.1  Þ C1 = 0.45
5.	Calculate slab corner curling stress (nighttime condition) for maximum wheel load condition.  Use 1° F/in. and load radius = 5.9 in.