UFC 3-260-02

30 June 2001

c. Assume that a 152-millimeter (6-inch) lean concrete base course will be used. The compressive

strength of the lean concrete is 20.6 MPa (3,000 psi), and the flexural modulus of elasticity is

13,788 MPa (2 106 psi). As with the previous example, the required thicknesses of plain concrete

pavement on both the nonstabilized and on the lean concrete base are determined and are shown in

columns 2 and 3 of Table 13-2. A value may then be selected for the required thickness of reinforced

concrete or the percentage of reinforcing steel and determine the other using Figure 13-1. If a percent

steel value of 0.20 is selected, the values of reinforced concrete from Figure 13-1 would be shown in

column 4 of Table 13-2. These values rounded for construction are listed in column 5. Then, reenter

Figure 13-1 with the rounded values of reinforced concrete to obtain the required percent steel shown in

column 6. The allowable slab lengths are determined from Equation 13-1 or Figure 13-1 using a

reinforcing steel with a yield strength of 413 MPa (60,000 psi) (column 7). If a reinforced concrete

thickness of 380 millimeters (15 inches) is selected for the type A, B, and C traffic areas and a thickness

of 255 millimeters (10 inches) is selected for the type D traffic area, then the required percent steel

determined from Figure 13-1 would be as shown in column 8. Column 9 presents the allowable lengths

or widths of slab for the reinforced concrete pavement.

13-7

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