TM 5-822-11/AFP 88-6, Chap. 7
CHAPTER 5
JOINT AND CRACK SEALING
5-1.
SEALING OPERATION.
tion to ensure it is firmly seated in the joint at the
a. General Information. When the joints and
proper depth. The backer material is cut where
cracks have been properly prepared and the mate-
two joints intersect to allow the material to lay
rials and equipment approved, the actual sealing
flat. Backer material is not required for preformed
can proceed. The joint or crack preparation and
seals, and they are generally not required for
the sealing operation are a continuous process.
cracks in bituminous pavements unless the crack
Prepared joints or cracks should not be left un-
depth is greater than 1 inch.
sealed for more than 1 day, and it is recommended
5-2.
Application Equipment.
that preparation not be completed on more joints
or cracks than can be sealed in the same working
a. Hot-Applied Sealing Equipment (Melter).
day. Sealing the joints or cracks the same day they
There are basically two types of hot-applied seal-
are prepared prevents unnecessary intrusion of
ing equipment. One is for the application of hot-
moisture, incompressibles, and dust that will re-
applied sealants that are solid at room temperature
quire further cleaning the next day. The sealing
and the other is for the application of hot-applied
operation for field molded sealants is the same
sealants that are liquid at room temperature. The
whether sealing joints or cracks in PCC
two types of equipment are not interchangeable.
or bituminous pavements. The operation consists
Figure 5-1 contains a schematic drawing of each
of installing the backer or separating material, the
in which the differences can be easily seen. All
equipment used to install the sealant, and the
applicators should be equipped with nozzles that
actual application of the sealant into the pavement.
are shaped to allow the sealant to seal the joint
b. Backer Material. The backer material must
from the bottom to the top of the reservoir. Field-
be inspected continually during the sealing opera-
poured hot-applied sealants must be heated to a
5-1
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