UFC 3-260-02

30 June 2001

and for the base course are 121, 176, and 303 MPa (17,500, 25,500, and 44,000 psi),

respectively. These values are shown in Figure J-3.

c. Relationships. The relationships indicated in Figure I-1 can be expressed as

%

&

(J-1)

%

%

where

n

= a layer in the pavement system

En = resilient modulus (in psi) of layer n

En+l = the resilient modulus (in psi) of the layer beneath layer n

t

= the thickness (in inches) of layer n for base-course materials and as

%

&

(J-2)

%

%

for subbase-course materials. Use of these equation for direct computation of modulus values for

the examples given above yields the value indicated in parentheses in Figures I-2 and I-3. It can be

seen that comparable values are obtained with either graphical or computational determination of

the modulus value for either material.

J-2

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