UFC 3-270-07
12 August 2002
2-2.4.3.16 Add the calcium chloride accelerator to the grout mix.
2-2.4.3.17 Place a 203-millimeter (8-inch) layer of 76-millimeter (3-inch) stone into the
grout mixture, producing a 406-millimeter (16-inch) layer of stone and grout. This stone
is worked into the grout by walking a dozer or high-speed tamping foot roller across the
repair.
2-2.4.3.18 A vibratory roller is used to percolate the grout up through the stone to the
surface.
2-2.4.3.19 The level of the stone and grout mixture should be within 19 millimeters
(0.75 inch) of the original pavement surface. Add equal parts of stone and grout until
the repair is level with the original pavement surface.
Figure 2-3. Stone and Grout Repair
406 mm (16 in) stone/grout mix
304 mm (12 in) crushed stone, 25 CBR
Backfill debris, 4 CBR
2-2.4.4
Stone and Grout Repair (Below Freezing Temperatures).
2-2.4.4.1 Special consideration must be made when placing the stone and grout
mixture in freezing temperatures. There are several methods that can be employed to
help ensure successful mission accomplishment.
2-2.4.4.2 Add additional calcium chloride accelerator (up to as much as 3 percent by
weight from the normal amount of 1 percent) to the solution of stone and grout to
decrease the set time.
2-2.4.4.3 Heat the aggregate; this can be done in a tent surrounding aggregate
stockpiles.
2-2.4.4.4 Heat the water. One possible method is to use immersion heaters. It is best to
heat both the water and the aggregate, rather than just one. This helps ensure that the
extremely cold condition of either component will not offset the heated condition of the
other. Do not mix the water and aggregate until the last possible moment.
2-2.4.4.5 Do not uncover the subgrade until immediately before placement to allow
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