Table 18-2.—Guide for Selecting a Stabilizing Additive
these characteristics are combined with certain
3) indicated at the intersection of the three material
restrictions relative to liquid limit (LL) and soil
percentages are used to enter table 18-2 to select the type
gradation contained in table 18-2, they provide guidance
of stabilizing additive based on the various restrictions
for the selection of the additive best suited for
and remarks. For example, a soil having a PI of 15 and
stabilization. Figure 18-1 is entered with the percentage
57-percent gravel, 26-percent sand and 7-percent fines
of gravel (percent material retained on the No. 4 sieve),
sand (percent material passing the No. 4 sieve and
fall in area 2B of figure 18-1. Table 18-2 indicates that
retained on the No. 200 sieve), and fines (percent
cement, lime, LCF, or bitumen could be considered.
material passing the No. 200 sieve) to determine the area
However, the PI of 15 eliminates bitumen, and the fact
in which the soil gradation falls. The areas (1A, 2C, and
that only 33 percent of the material passes the No. 4
18-4
