UFC 3-270-07
12 August 2002
heat to be retained. This necessitates a change in repair priorities since several craters
cannot be worked on concurrently (as their subgrades would be left exposed while
awaiting grout); rather, one crater is completely repaired before moving on to repair the
next.
2-2.4.4.6 Place an insulated blanket over the finished surface. One possible
composition of this blanket is a layer of impervious membrane, approximately 254
millimeters (10 inches) of straw or hay, followed by an additional layer of impervious
membrane.
2-2.4.5
Concrete Repair. See Figure 2-4.
2-2.4.5.1 This type of repair may be used in lieu of or as a replacement for both the
crushed stone and sand-grid repairs when additional resources are available. Uniform
compaction of backfill material is critical.
2-2.4.5.2 Clear debris from around the crater at least 6 meters (20 feet) in all directions
to allow identification of the upheaved pavement surface. Identification and removal of
all upheaved or damaged pavement is critical. It cannot be rolled down flush with
the existing pavement surface and left. The upheaved pavement will eventually
break up and create additional problems adjacent to the crater repair.
2-2.4.5.3 Perform a profile measurement and visual inspection to identify and mark
upheaval around the crater.
2-2.4.5.4 Square to vertical the sides from the original pavement surface down to a
minimum depth of 304 millimeters (12 inches).
2-2.4.5.5 All debris material in excess of 304 millimeters (12 inches) must be removed
or reduced in size.
2-2.4.5.6 Standing water in the crater must be pumped out, if possible.
2-2.4.5.7 Any reinforcing material protruding from the original pavement must be cut off
and removed.
2-2.4.5.8 Backfill the crater with useable debris and level to exactly 711 millimeters (28
inches) below the original pavement surface to support C-17 operations, or 457
millimeters (18 inches) to support C-130 operations.
2-2.4.5.9 Backfill material must be compacted to a minimum 4 CBR.
2-2.4.5.10 If settling problems are anticipated, a geomembrane fabric is recommended
for use between dissimilar backfill and the next layer of material.
2-2.4.5.11 Place a layer of crushed stone (38 millimeters [1.5 inches] minus) over the
backfill material. This layer should be 406 millimeters (16 inches) thick to support C-17
2-12