Onsite Use of Recycled Asphalt Pavement Materials and Geocells to ...

The permanent deformation was obtained after unloading of each cycle. Figure 4.21
presents the measured permanent deformations of the pavement at the surface, at the top of the
base, and at the top of the subgrade. The surface deformations at different distances from the
center were obtained by the displacement transducers. It is shown that the surface permanent
deformation was higher at the center and decreased with the distances of 25 and 50 cm away
from the center. The elastic deformation (i.e., the rebound during the unloading of each cycle)
was higher at the beginning of loading and then decreased slightly at a small rate until the end of
the test as shown in figure 4.22. The elastic deformation was much smaller than the permanent
deformation and was less than 10% of the permanent deformation at the end of the test.
Permanent deformation (mm.)
30
25
20
15
10
5
0
-5
0 2000 4000 6000 8000 10000 12000 14000 16000
Number of loading cycle
Figure 4.21 The permanent deformation versus the number of loading cycles for the 15 cm thick
geocell-reinforced RAP base section (hard subgrade)
65
Surface at center Surface at 25 cm
Surface at 50 cm Surface at 75 cm