Page 116 - Mechanics of Asphalt Microstructure and Micromechanics

108 Ch a p t e r F o u r

FIGURE 4.7 Macro-strain contours for Image 9.

for one triangle (Figure 4.7a and Particles 9, 11, and 14 in Figure 4.6a) are summarized
in Table 4.3. In addition, the ratio of the mastic area to solid area or mastic solid area
ratio (MSAR) for each image, both before and after deformation, was also calculated
and is summarized in Figure 4.8. It is noted that in these calculations, the sign of the
strains follows the convention that tensile strain is positive. Thus, positive volumetric
strain indicates dilation and vice versa. From Figure 4.8, it can be seen that MSAR in the
zones close to the loading hose increased (Images 9, 10, 13, and 14), whereas MSAR in
the zones outside of these images decreased (Images 4, 6, 17, and 18). MSAR in the
plane strain case is equal to volumetric strains. Therefore, to a certain degree, the in-
crease of this ratio is equivalent to dilation while the decrease of this ratio is equivalent
to contraction.