chapter 3 rigid pavement - DOT On-Line Publications - Department ...

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ST-ON. Proper construction techniques must be followed to
ensure that the compression seals will perform as intended.
Improper installation procedures are a primary cause of premature
failures of these seals. Close attention must also be paid to
the manufacturer's recommendations.
The joint faces must be vertical, so that the seal does not work
itself up and out of the joint. Any spalls at the joint should
be patched prior to installation of the compression seal.
(Spalls less than l/4-inch may remain; however, the seal should
be recessed sufficiently to avoid the spalled area.)
Irregularities in the joint width could reduce the pressure on
the seal to the point that it would no longer remain in
compression.
It is recommended that the concrete surfaces at the joint be dry
prior to installation of the compression seal. The joint should
be air-blasted to remove any debris. Both the air temperature
and the temperature of the pavement should be above freezing.
Prior to installing the compression seal, a lubricant-adhesive
should be applied to either the joint faces or the seal.
material primarily serves as a lubricant to facilitate the This
installation process. This material also cures to form a weak
adhesive, which helps keep the seal at the proper height.
However, it does not provide any tensile strength.
The compression seal should be adequately recessed, so that it
won't be damaged by traffic. The joint edge may be beveled to
reduce spalling. A l/4-inch radius bevel or a l/b-inch straight
bevel is sufficient. The compression seal should be recessed
approximately l/a-inch below the bottom of the bevel. When the
joint edge is not beveled, the seal should be recessed from
l/a-inch to 3/8-inch beneath the top of the slab. The seal may
be recessed up to l/a-inch if grinding of the concrete pavement
is anticipated in the future. While this additional depth should
prevent the seal from being damaged by the grinding operation, it
may allow incompressibles to accumulate and cause spalling.
joint resenroir should be deep enough to allow the seal to be The
compressed without extruding to an elevation where it will be
exposed to traffic.
Care should be taken to not stretch the seal during the
installation process. A stretched seal will not perform as well
or as long as a properly installed seal. The seal should also
not be twisted, as intimate contact must be maintained between
the seal and joint faces over the full length of the seal. Most
compression seal manufacturers have developed installation
equipment which do not stretch, twist or damage the seals. This
type of equipment should be used.
3.3.5