28.03.2013 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

3.6.6 Vane Shear Test<br />

Figure 3.13 Cyclic loading wave form (from Pokharel 2010)<br />

Vane shear tests (ASTM D2573-08) were carried out <strong>to</strong> check the undrained shear<br />

strength <strong>of</strong> subgrade during the preparation <strong>of</strong> the subgrade for test sections. The size <strong>of</strong> the vane<br />

was 18.8 mm in diameter <strong>and</strong> 28.5 mm in length. The vane shear test as shown in figure 3.14<br />

was used <strong>to</strong> evaluate the undrained shear strengths (Cu) at depths <strong>of</strong> 10 cm, 18 cm, <strong>and</strong> 25 cm<br />

from the <strong>to</strong>p <strong>of</strong> the prepared subgrade section at five different locations, <strong>and</strong> ensure the quality<br />

<strong>and</strong> consistency <strong>of</strong> the prepared subgrade <strong>to</strong> attain the desired strength. The obtained undrained<br />

shear strength by the vane shear test was used <strong>to</strong> estimate the CBR value <strong>of</strong> the prepared<br />

subgrade. If the desired value <strong>of</strong> strength was not met, the subgrade was re-prepared until the<br />

desired strength was reached. The following relationship established for this subgrade by<br />

Pokharel (2010) was used <strong>to</strong> estimate the subgrade CBR value using the undrained shear strength<br />

(Cu) by the vane shear test:<br />

CBR(%) (3.1)<br />

20.<br />

5<br />

38<br />

Cu

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!