PerRoad: Material Properties
Each material type has range of acceptable layer moduli and Poisson ratios as shown in the tables below. Seasonal adjustments may also be made and default values are built into PerRoad for the granular base and subgrade materials. Refer to the section below titled Seasonal Adjustments. Finally, adjustments to the AC modulus as a function of temperature may be made and default functions are built into PerRoad, as well. Click here for more details on temperature adjustments.
|
Material |
Description |
Minimum Modulus, psi |
Maximum Modulus, psi |
|
AC |
Asphalt
Concrete |
50,000 |
4,000,000 |
|
Cracked AC |
Cracked
Asphalt Concrete |
50,000 |
500,000 |
|
PCC |
Portland
Cement Concrete |
2,000,000 |
7,000,000 |
|
Rubb PCC |
Rubblized
Concrete |
40,000 |
700,000 |
|
C and S
PCC |
Crack and
Seated Concrete |
200,000 |
800,000 |
|
B and S
PCC |
Break and
Seated Concrete |
250,000 |
2,000,000 |
|
G.B. |
Granular
Base |
5,000 |
50,000 |
|
Soil |
Soil |
3,000 |
40,000 |
|
Rock |
Bedrock |
500,000 |
1,000,000 |
|
Other |
User
Defined |
50 |
10,000,000 |
|
Material |
Minimum Poisson |
Default Poisson |
Maximum Poisson |
|
AC |
.15 |
.35 |
.4 |
|
Cracked AC |
.15 |
.35 |
.4 |
|
PCC |
.14 |
.18 |
.25 |
|
Rubb PCC |
.14 |
0.2 |
.25 |
|
C and S PCC |
.14 |
0.2 |
.25 |
|
B and S PCC |
.14 |
0.2 |
.25 |
|
G.B. |
.30 |
.4 |
.45 |
|
Soil |
.2 |
.45 |
.5 |
|
Rock |
.1 |
.15 |
.25 |
|
Other |
.1 |
.35 |
.5 |
Granular Base Default Adjustments
The Fall modulus is 1.3 times the Summer Modulus.
The Winter modulus is 2 times the Summer Modulus.
The Spring modulus is 50% of the Summer Modulus.
The Second Spring modulus is 80% of the Summer Modulus.
Subgrade Soil Default Adjustments
The Fall modulus is 1.25 times the Summer Modulus.
The Winter modulus is 2 times the Summer Modulus.
The Spring modulus is 1.25 times the Summer Modulus.
The Second Spring modulus is 1.1 times the Summer Modulus.