So far, we have carried out a series of tests. Let us sum up all the data at our disposal as follows:
• Air voids in the compacted coarse aggregate VCAdrc
• Initial (or adjusted if needed) content of binder
We have also made a series of compacted SMA samples. Now it is time to determine the following features for them:
• Bulk density of the compacted SMA sample
• Maximum density of the SMA mix
• Content of air voids in the compacted SMA samples (Va)
• Content of VMA
• Content of air voids in the coarse aggregate of the aggregate mix
(VCAMIX)
Among these features, only VCAMIX is a new one. It is vitally important to understand the differences between the terms VCAdrc, VMA, and VCAMIX. All of them describe voids in an aggregate mix or one portion of the aggregate mix. Figures 7.9 through 7.11 show their graphic representations. The following is a brief description of the three:
• VCAdrc—content of air voids in the compacted coarse aggregate (coarse aggregate portion of the total aggregate mix, retained on the BP sieve)
vcadrc Volume of air voids in coarse aggregate
Volume of coarse grains
FIGURE 7.9 Definition of VCADrc—the content of air voids in a compacted coarse aggregate.
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VCAMIX—content of air voids in the coarse aggregate of a compacted SMA mixture—that is, the volume of everything but the coarse aggregate in the SMA mixture, or the volume of binder, filler, fine aggregate, and air voids)
• VMA—content of air voids in an SMA aggregate mix, equal to the sum of air void volume in a compacted SMA plus the volume of effective binder, excluding filler and fine aggregate
