ETL 1110-1-177
31 Dec 96
(2) Using the grout material proportions specified in
CEGS-02548 and shown below, develop a matrix of initial job-mix
formulas for laboratory viscosity testing. The goal of the grout
mix design is to produce a material formulation which results in
a Marsh Flow Cone viscosity of 8.0 to 10.0 seconds. The initial
formulations should ensure that a grout formulation can be
produced with a Marsh viscosity no greater than the 10.0 seconds
maximum. This is accomplished by testing grout formulations with
relatively high w/c ratios and the maximum allowable amount of
resin additive. Typical initial grout formulations tested in a
mix design evaluation are shown below.
Batch Percentage by Weight
CEGS-02548
Material
Limits
Trial 1
Trial 2
Trial 3
Portland Cement
34-40
37.0
36.0
35.0
Silica Sand
16-20
18.0
17.8
17.7
Fly Ash
16-20
18.0
17.9
17.8
Water
22-26
24.0
25.0
26.0
Resin Additive
2.5-3.5
3.0
3.3
3.5
(3) Although the grout's w/c ratio is unspecified, the
desirable w/c range is 0.65 to 0.75. Lower w/c values are more
desirable to reduce the risk of shrinkage cracking and for higher
grout strengths. Higher w/c ratios are sometimes necessary to
produce grouts with Marsh Flow viscosities less than the
10.0-second maximum value. Therefore, the focus of the initial
grout viscosity tests is to determine the minimum W/C ratio that
will produce a grout viscosity less than or equal to 10.0
seconds. It is important to remember that the resin additive
serves as a plasticizer which reduces grout viscosity while
reducing the amount of water required.
(4) The standard laboratory grout batch size should be in
the 4,000- to 5,000-g range. Calculate the material batch
weights based on the desired proportions. Multiple grout
viscosity tests are facilitated by first blending the dry
ingredients (cement, sand, fly ash) for each test sample and then
adding the appropriate amount of water and resin additive during
the mixing process. These dry- ingredient batches should be kept
in air-tight containers to prevent loss of material or
contamination before mixing. Two replicate samples per blend are
appropriate for grout viscosity testing.
B-4
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