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

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The pr<strong>of</strong>iles <strong>of</strong> the HMA surfaces as shown in figure 4.47 were measured from the<br />

reference beam before <strong>and</strong> after the cyclic plate load test. It shows that a depression (equivalent<br />

<strong>to</strong> rutting under traffic) developed under the loading plate <strong>and</strong> some heaving occurred away from<br />

the loading plate after the test.<br />

Depth (cm.)<br />

8<br />

10<br />

12<br />

14<br />

16<br />

18<br />

-100 -80 -60 -40 -20 0 20 40 60 80 100<br />

Distance from center (cm.)<br />

Figure 4.47 Pr<strong>of</strong>iles <strong>of</strong> the HMA surface before <strong>and</strong> after the test for the 30 cm thick<br />

unreinforced RAP base section<br />

The permanent deformation was obtained after unloading <strong>of</strong> each cycle. Figure 4.48<br />

presents the measured permanent deformations <strong>of</strong> the pavement at the surface, at the <strong>to</strong>p <strong>of</strong> the<br />

base, <strong>and</strong> at the <strong>to</strong>p <strong>of</strong> the subgrade. The difference in the permanent deformations between the<br />

HMA surface <strong>and</strong> the base is the compression <strong>of</strong> the HMA surface while that between the base<br />

<strong>and</strong> the subgrade is the compression <strong>of</strong> the base course. At the end <strong>of</strong> the test, the permanent<br />

deformation <strong>of</strong> the subgrade was approximately 50% <strong>of</strong> the <strong>to</strong>tal permanent deformation. The<br />

surface deformations at different distances from the center were obtained by the displacement<br />

transducers while the deformations at the <strong>to</strong>p <strong>of</strong> the base <strong>and</strong> subgrade were obtained by the tell<br />

tales. It is shown that the surface permanent deformation was higher at the center <strong>and</strong> decreased<br />

86<br />

Before Test<br />

After Test

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