TM 5-822-11/AFP 88-6, Chap. 7
compression seals are removed, refacing is gener-
that has been used successfully to remove residual
ally not required unless the joint width is smaller
sealant and debris is "dry" sawing. Dry sawing is
than specified in the plans.
accomplished by using a diamond blade concrete
d. Rebuilding Defective Joints. Joints that are
saw without water. The blade of the concrete saw
wider than 1 inch or that are severely spalled
is placed against one of the joint faces to allow the
should be examined to determine if rebuilding is
removal of a minimal amount of concrete. After
required. If preformed elastomeric compression
one joint face is completed, the opposite joint face
seals are being considered, the joint sidewalls
is dry sawed. The blades should be inspected often
must be vertical and parallel. In contrast, field-
to ensure they have not become damaged. Cleaned
poured sealants may perform adequately with
joints should appear as shown in figure 4-12. A
some minor spalling present. Joints should be
rotary wire brush should not be used to clean
rebuilt in accordance with TM 5-624/AFR 85-8
joints especially when the joint contains residual
using appropriate materials. A rebuilt joint is
joint sealant. The wire brush scrapes the joint
shown in figure 4-16.
faces producing cement dust. The brush may also
e. Cleaning Joints. Once the old sealant has
become coated with old joint sealant which will be
been removed and any required refacing or re-
smeared over the joint faces covering the cement
building of the joints has been accomplished, the
dust. The smeared joint sealant and dust produces
joints are ready for cleaning. The joints can be
a layer that prevents the new sealant from
cleaned using the multiple pass sandblasting or
contacting the joint faces and developing a bond to
waterblasting technique previously described. If
the concrete. The final step of cleaning the joint is
waterblasting is used, the joint must be thoroughly
airblowing to remove remaining dust and debris.
dried to remove all moisture before inserting the
Airblowing should be accomplished immediately
backer material and sealant. Another technique
prior to installing the backer or separating
4-7
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