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

Because a larger Seal was used, would a sawcut width of
0.375 inch work regardless of the temperature at
installation?
Case 1: Insufficient compression
(Seal width - Max. joint opening (JO,) ) + Seal width = C,,,
( 0.688 - JO, ) + 0.688 = 0.2
JO, = 0.688 - ( 0.2 ) ( 0.688 )
J%R = 0,55 inch
JQUI - SC = allowable movement
0.55 - 0.375 = allowable movement
0.175 inch = allowable movement
0.175 inch 1 0.15 inch (anticipated joint movement)
The seal will not be undercompressed.
Case 2: Compression set
(Seal width - Min. joint opening (JO,)) i Seal width = C,
( 0.688 - JO- ) + 0.688 = 0.55
JOrr,n = 0.688 - ( 0.55 ) ( 0.688 )
JOti - 0.31 inch
SC - JO* - allowable movement
0.375 - 0.31 = allowable movement
0.065 inch = allowable movement
0.065 inch ( 0.15 inch (anticipated joint movement)
The seal may undergo compression set.
The acceptable installation temperature range
= [ allowable movement + total movement ] * temp range
= ( 0.065 + 0.15 ) l 76’
- 33’
90’ - 33’ = 57’
The seal will not undergo compression set so long as
the joint is sawed and sealed when the pavement
temperature is greater than 57.F. It iS recommended
that the specifications be revised to limit the
installation operation to temperatures above 57.F or
the design revised to provide a shorter joint spacing.
3.3.9