UFC 3-250-03
15 May 2001
35 percent range of values. The voids total mix of laboratory specimens and ungrouted field cores can
be calculated using the following formula:
WTair (1)
VTM ' 1 &
100
Volume SGT
where
VTM = voids total mix
Wtair = dry weight of specimen
Volume = /4 D2H (measured)
D = diameter
H = height
SGT = theoretical specific gravity
b. Cement grout. The slurry grout job mix formula can be developed using the range of properties
given in table 8-4. Using these proportions, the following procedure is used. The slurry group samples
are prepared in the laboratory by first dry mixing the cement, sand, and fly ash in a blender until they are
thoroughly mixed. The appropriate amount of water is then added, and the grout mixture is blended for
5 minutes. After this 5 minute mixing period, the PL7 resin additive is added and mixed with the grout
for an additional 3 minutes. Immediately after the 3 minute mixing period, the grout is poured into the
Marsh flow cone and tested for viscosity. A Marsh cone has dimensions of 155 millimeters (6.2 inches)
base inside diameter, tapering 315 millimeters (12.6 inches) to a tip inside diameter of 10 millimeters
(0.4 inch). The 10 millimeter diameter neck should have a length of 60 millimeters (2.4 inches). The
viscosity, in seconds, is measured for each sample and three different batches of each blend are tested
to obtain an average viscosity value. The requirements for viscosity of the grout are given in table 8-5.
The individual components of the grout may be adjusted within the prescribed tolerances listed in
table 8-4 to obtain a desired grout viscosity.
Approximately 10 to 13 kilograms (22 to 28 pounds) of mixed slurry grout will fill in 0.8 square
meters (1 square yard) for each 25 millimeters (1 inch) of thickness of open graded asphalt mixture with
25 to 35 percent voids total mix.
Table 8-4
Resin Modified Cement Slurry Grout Mixture Proportions
Material
Percent by Weight
Silica sand
16 - 20
Fly ash
16 - 20
Water
22 - 26
Type I cement
34 - 40
Cross polymer resin
2.5 - 3.5
8-4
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