Example of Continuously Reinforced Concrete Pavement Design

Pavement Design for Airfields - index
Page Navigation
299

UFC 3-260-02

30 June 2001

8. JOINT SEALING. The only joints requiring sealing in continuously reinforced concrete pavements

will be longitudinal construction joints and expansion joints. Transverse construction joints need not be

sealed since they will behave as conventional volume-change cracks that are present elsewhere in the

pavement. Joint sealing membranes will be as specified for plain concrete pavements.

9. EXAMPLE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT DESIGN. It is required

that a pavement be designed as an Air Force medium-load airfield. Types A and B traffic areas are

designed for the F-15 at 23,130 kilograms (81,000 pounds), the C-17 at 263,000 kilograms

(580,000 pounds), and the B-52 at 181,440 kilograms (400,000 pounds). Types C and D traffic areas

and overruns are designed for the F-15 at 27,555 kilograms (60,750 pounds), the C-17 at

197,280 kilograms (435,000 pounds), and the B-52 at 136,080 kilograms (300,000 pounds). Types A, B,

and C traffic areas are designed for 100,000 passes of the F-15, 400,000 passes of the C-17, and

400 passes of the B-52. Type D traffic areas and overruns are designed for 1,000 passes of the F-15,

4,000 passes of the C-17, and 4 passes of the B-52. On-site and laboratory investigations have yielded

the following data required for design:

Subgrade = silty sand (SM)

Modulus of subgrade reaction = 54 kPa/mm (200 lb/in.3)

Flexural strength = 4.83 MPa (700 psi)

The thickness of the continuously reinforced concrete pavement will be the same as required for plain

concrete according to the procedures set forth in Chapter 12. The required thicknesses are therefore as

follows:

Traffic Area

Calculated Thickness, mm (in.)

Design Thickness, mm (in.)

396 (15.6)

405 (16.0)

388 (15.3)

394 (15.5)

297 (11.7)

305 (12.0)

D and Overruns

238 (9.4)

241 (9.5)

Additional data required for determining the percent longitudinal steel are as follows:

Tensile strength of concrete (from Figure 15-2) = 3.45 MPa (500 psi)

Yield strength of steel = 414 MPa (60,000 psi)

Coefficient of thermal expansion of concrete = 7.2 10-6 millimeters per millimeter per degree

Celsius (4 10-6a inches per inch per degree Fahrenheit)

Modulus of elasticity of steel = 206 820 MPa (30 106 psi)

Seasonal temperature differential of pavement = 72 degrees Celsius (130 degrees Fahrenheit)

15-4