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<br />(a) (b) <br />Figure 6. (a) Example of core extracted from pavement for study and (b) close-up of core shows evidence of past <br />chip seal treatments <br />The subsections below detail the laboratory test procedures applied in this study; data and results from <br />these tests are presented in Chapter 3. <br />2.3.1 Testing to determine volumetric properties of asphalt samples <br />Six samples from each of each of the 18 locations were used for volumetric analysis of the underlying <br />asphalt. Specimens were compacted according to AASHTO T 312 for: <br />Maximum theoretical specific density (G) testing according to AASHTO T 209 and ASTM D <br />mm <br />2401 and <br />Bulk specific gravity (G) testing according to AASHTO T 166. <br />mb <br />In preparing cores for G testing under AASHTO T 209, the cores were trimmed to remove cut <br />mm <br />aggregate, and testing was conducted with between 2000 and 2050 grams of material from the center <br />of the core, which is briefly heated to 230°F to dry moisture from the core sample. <br />Given the results of the G and G tests, properties such as the percent air voids and the effective <br />mmmb <br />specific gravity were calculated. These properties in turn were used to determine the percent voids in <br />mineral aggregate (VMA) and the percent voids filled with asphalt (VFA). Finally, given surface area <br />characteristics for the sieve sizes of the aggregate, the average film thickness (AFT) was calculated. <br /> <br />13 <br /> <br />