TM 5-822-11/AFP 88-6, Chap. 7
b. If the working range of the sealant is less
than the working range of the joint, the sealant
will be overstressed and fail. When it is deter-
mined that the working range of the joint is larger
than the sealant working range, the joint width
should be increased to allow the working range of
the sealant to be larger than the working range of
the joint.
C-2. Field-Poured Sealants.
C-3. Preformed Elastomeric Compression
a. Field-poured sealants have a working
Seals.
expansion-compression range of approximately 20
a. Working Range. Preformed elastomeric
percent. For a joint width of 0.5 inches, the
compression seals must remain in compression at
working range of the sealant would be:
all times, whether the joint is opened or closed.
The seal must remain compressed at least 20
0.5 0.5(0.2) = 0.6 to 0.4 inches
percent when the joint is open but not compressed
more than 80 percent of the seal width when the
The working range of the sealant is illustrated in
joint is closed. The working range of the joint can
table C-2.
be used to calculate the maximum and minimum
width of the seal that may be used in a joint. The
calculations are as follows:
(1) Seal Widthmax = (Minimum Joint Width)
(5.0) (not compressed more than 80 percent)
(2) Seal Widthmin = (Maximum Joint Width)
(1.2) (remains in compression at least 20
percent)
C-2
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