12 August 2002
2-22.214.171.124 Crushed Stone Repair Procedures. See Figure 2-1.
(1) 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 upheaval or damaged pavement is critical. It cannot be rolled down
flush with the existing pavement and left. The upheaved pavement will eventually
break up and create additional problems adjacent to the crater repair.
(2) Perform profile measurement and visual inspection to identify and mark
upheaval around the crater.
(3) Remove upheaved pavement using an excavator with bucket or moil
point attachment, and the front-end loader. The dozer may also be used, depending on
the runway surface.
(4) All debris material in excess of 304 millimeters (12 inches) must be
removed or reduced in size. Breaking the pavement into smaller pieces will minimize
the potential for voids and settling problems in the future.
(5) Push unusable debris at least 9 meters (30 feet) off the MOS and pile no
higher than 0.9 meter (3 feet).
(6) Place backfill material into the crater in accordance with the repair
procedure chosen. Note: If settling problems are anticipated, placement of membrane
fabric between dissimilar backfill materials is recommended.
(7) Fill and compact the crater with crushed stone material, placing it in lifts
approximately 152 to 177 millimeters (6 to 7 inches) thick. For C-17 operations, limit the
aggregate size to a maximum of 25 millimeters (1 inch) in the top 152 millimeters (6
inches) of the crushed stone repair. Overfill the crater by approximately 76 millimeters
(3 inches) above the original pavement surface height. Compact each lift of crushed
stone using a minimum of four passes of a single drum vibratory roller or two passes
with a 10-ton vibratory roller. One pass of the roller means traveling across and back in
the same lane. If the crushed stone material is placed upon soft subgrade materials, it
may be beneficial to separate the material using geomembrane fabric and place the
crushed stone material in thicker lifts. In any case, the crushed stone should be
compacted with a minimum of four passes of a single drum vibratory roller or two
passes of a 10-ton vibratory roller per each 152 millimeters (6 inches) of thickness. A
457-millimeter (18-inch) crushed stone layer should receive a minimum of 12 passes
with a single drum vibratory roller or six passes with a 10-ton vibratory roller prior to cut
for the final grade.
(8) Grade the compacted crushed stone to approximately 25 millimeters (1
inch) above the pavement surface.
(9) Compact the crushed stone using two passes of a single drum vibratory
roller or one pass with a 10-ton vibratory roller. The crushed stone layer should have a