Civil Engineering Reference
In-Depth Information
Time
Time
FIGURE 9.37
Typical load and horizontal deformation versus time during the
resilient modulus test.
Typical resilient modulus values of asphalt concrete are 6.89 GPa, 4.13
GPa, and 1.38 GPa (1000 ksi, 600 ksi, and 200 ksi) at temperatures of 5°C,
25°C, and 40°C, respectively. The diametral tensile resilient modulus test is
very sophisticated, because it measures very small deformations. Therefore,
extreme caution must be exercised to align the specimen between the load-
ing trips and to reduce possible rocking. Also, the load magnitude must be
small enough to reduce the possibility of permanent deformation in the spec-
imen, yet large enough to obtain measurable deformation.
Sample Problem 9.7
The resilient modulus test was performed on an asphalt concrete specimen and the
following data were obtained:
diameter
=
4.000 in.
thickness
=
2.523 in.
repeated
sum of recoverable horizontal
load
=
559 lb
10
-
6
in.
deformations
=
254
*
Assuming a Poisson's ratio of 0.35, calculate the resilient modulus.
Solution
P
1
0.27
+ y
2
10
-
6
M
R
=
=
559
*
1
0.27
+
0.35
2
/
1
2.523
*
254
*
2
t.
¢
H
=
541,000
psi
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