Lesson 5/Learning Event 3
Step 1
Determine the percentage asphalt content (AC) for each Marshall property. Go to Table 9,
column 4, High Pressure, to find where to enter the graph.
Stability. The percentage AC for stability is determined by the peak of the curve. From the
peak of the curve a vertical line is drawn down to the percent AC line. In this case the reading
for maximum stability is approximately 4.3 percent (Figure 14).
Unit Weight. The percent AC for unit weight is determined by the peak of the curve. From the
peak of the curve a vertical line is drawn down to the percent AC line. Figure 15 shows that the
reading for maximum unit weight in this case is 4.5 percent.
FIGURE 14
FIGURE 15
Percent Voids Total Mix. In Figure 16, the percent voids total mix is 4 per cent. Percent voids
total mix curve is entered at the left at 4 percent, and a horizontal line is drawn to the right to
intersect the curve. From this inter section, a line is drawn vertically down to the percent AC
line, where AC is found to be 5 percent.
Percent Voids filled with AC. Figure 17 shows the percent voids filled with AC is 75 percent.
Thus, the curve is entered at the left at 75 percent and a horizontal line is drawn to the right to
intersect the curve and down to the percent AC line. In this example the value is 4.9 percent AC.
65
Previous Page
