TM 5-822-11/AFP 88-6, Chap. 7
on hand for the various joint sizes. The tools must
temperature should be noted, and the sealant
be rectangular, not V-shaped, and the mounting
agitator and temperature devices should be exam-
assembly must not be rigid. The tool should have
ined to ensure they are operating. If possible, a
some mobility to move laterally and vertically to
direct reading on the sealant temperature should
prevent the tool from chipping and spalling the
be made to verify the reading on the in-place
joint.
thermometers. The sealant will often form an
insulation around the in-place thermometer yield-
b. Vertical Spindle Router. If a router is to be
ing incorrect readings. The continuous agitators
used to clean and open cracks in PCC, there
should be examined to prevent overheating and
should be sufficient bits of various sizes on hand
ensure the entrapment of air in the sealant does
to work with the cracks that exist. The equipment
not occur. The manufacturer's recommended
must be able to follow the crack and widen it to
safety procedures for installing the sealant should
the desired width without spalling the concrete
be followed. Safety cannot be overemphasized.
around the crack.
Some hot-applied sealants can emit toxic fumes
c. Sawing or Refacing. The blades must be on
when they are heated; therefore, the
the same arbor and spaced to produce a joint or
manufacturer's recommendations concerning
prepare a crack to the necessary depth and width.
operator safety must be followed.
A water supply must be available to cool the
f. Cold-applied Sealant Applicator. Two-
blades during operation. The saw cuts must not
component applicators will have two reservoirs to
spall the concrete. The depth and width must be
observe with the items being evaluated similar to
uniform along the joint and the saw cut must be
those evaluated for a hot-applied sealant. A critical
straight (i.e., the cut must not wander from one
factor in applying two-component sealants is the
side of the joint to the other). When dry sawing is
mixing head on the sealant wand and the
used, only one blade is used and the water supply
proportioning of the sealant. The proportions
is not necessary. It should be noted that dry
being mixed must be checked periodically by
sawing is a cleaning or scrapping of the joint face
collecting the two components in separate cans and
and is not an actual sawing. This is the reason
measuring the volume of sealant collected in each
water is not needed when dry sawing; however,
can. The proportions should be checked against
the blades should be inspected often to ensure they
the manufacturer's recommendations. Single
are not damaged.
component materials normally use an air
d. Sandblasting or Air Blowing. The physical
compressor and an extrusion system to insert the
requirements of the sandblasting equipment have
sealant into the joint. The evaluation of the air
been previously discussed. Before sandblasting be-
compressor is the same as listed for sandblasting.
gins, one should make certain that the operator is
Neither the two-component nor the single-
wearing all of the required protective clothing.
component equipment should have a recirculating
When sandblasting begins, one should examine all
system.
pressure gauges to ensure the correct line pressure
g. Preformed Compression Seal Applicator.
is being maintained. The positioning fixtures on
The preformed seal can be installed by hand or
the nozzles should also be examined to ensure the
with automated equipment. Both operations
nozzle is being supported over the joint or crack,
require placing the lubricant/adhesive on the joint
allowing the sand to thoroughly clean the faces.
faces and the seal. The seal must be placed at the
The joint faces and the pavement surface up to
correct depth without twisting, compressing, or
approximately 1/2 inch away from the joint or
stretching the seal by more than 2 percent. For
crack must be dry and free from any dirt, film, or
example, a 50-foot long seal should be no longer
oil. If oil or water is present on the joint face, one
than 51 feet or shorter than 49 feet when installed.
should check the compressor to ensure that all of
The applicator must have two axles for proper
the traps are clean and working and that none have
stability during the installation of the seal. One-
been removed or bypassed. The same consid-
axle applicators have a tendency to wobble and
erations apply to the compressor used for
place the seal unevenly.
airblowing the joints or cracks.
h. Power Broom. The sweeping equipment
e. Hot-Applied Sealant Applicator. The equip-
must be vacuum equipped to pick up debris on the
ment must be examined to determine if the correct
pavement surface that could contaminate the joint
applicator is being used. Applicators that are
or crack.
designed to melt and install solid hot-applied
6-3. Joint Preparation.
sealants cannot be used to heat and install liquid
hot-applied sealants and vice-versa. The length of
a. Once the equipment has been evaluated and
time it takes the equipment to reach the application
approved, the sealing project can begin. If any
6-2
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