TM 5-822-11/AFP 88-6, Chap. 7
(7) Cracks greater than 1 inch wide can
prepare for sealing. However, if the crack is not
be temporarily repaired using bituminous concrete
correctly prepared, the sealant will not function
as a patch. Bituminous concrete is an
much beyond the first cold season. The procedure
incompressible material and will give adequate
for sealing cracks in bituminous pavement in
performance for only a limited time. The patched
similar to sealing cracks in concrete pavement and
crack must be observed carefully to ensure that the
includes sealant removal (when resealing),
crack is functioning properly and the bituminous
routing, crack repair, and cleaning.
mix is not creating problems. For a permanent
b. Sealant Removal or Routing. Sometimes it is
repair, the crack must be rebuilt as a joint.
possible to remove the old sealant and form the
e. Cleaning. Once the crack has been routed
new sealant reservoir in the same operation. In
and damaged areas have been repaired, it is
most cases, however, the old sealant has to be
cleaned in the same manner as the joints (i.e.
removed using hand tools and then the crack is
sandblasted or waterblasted and air blown), to
routed. The crack can be routed using a vertical
achieve the same level of cleanliness attained in
spindle router or a rotary impact router equipped
joint cleaning.
with carbide tipped bits. These devices are de-
f. Backer Material. Cracks that have a depth
signed to form a sealant reservoir while
greater than inch will require a backer material
maneuvering along the irregular direction of the
to maintain the proper shape factor and to support
crack. Routing is also required when the edges of
the sealant.
the crack are raveled or contain loose aggregate in
order to provide sound asphalt concrete for the
sealant to adhere. General guidelines for routing
4-5. Preparing Cracks in Bituminous
cracks are based upon the width of the crack. The
Pavement.
general guidelines are as follows.
a. Cracks often have irregular dimensions and
(1) Hairline cracks (less than inch) are
directions that make them difficult to properly
not routed.
4-10
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