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

?%‘.4 TECHWIC.4L ADVISORY T 3040.30
\iovernber 30, 1990
(5)
7. DPANSION JOINTS
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Figure 1. Recoarnended Keyway Dimensions
Bending of tiebars is not encouraged. Where bending of the
tiebars would be necessary, it is reconmnended that a two-
part threaded tiebar and splice coupler system be used in
lieu of tiebars. If tiebars must be bent and later
straightened during construction, Grade 40 steel should be
used, as it better tolerates the bending. It may be
necessary to reapply a corrosion-resistant coating to the
tiebars after they have been straightened. When pull-out
tests are performed, they should be conducted after the
tiebars have been straightened.
(6) It is recommended that longitudinal construction joints be
sawed and sealed. The reservoir dimensions should be the
same as those used for the longitudinal joints.
a. Good design and maintenance of contraction joints have virtually
eliminated the need for expansion joints, except at. fixed objects
such as structures. When expansion joints are used, the pavement
moves to close the unrestrained expansion joint over a period of a
few years. As this happens, several of the adjoining contraction
joints may open, effectively destroying their seals and aggregate
interlock.
b. The width of an expansion joint is typically 3/4-inch or more.
filler material is commonly placed 3/4- to l-inch below the slab
surface to allow space for sealing material. Smooth dowels are
the most widely used method of transferring load across expansion
joints. Expansion joint dowels are specially fabricated with a
cap on one end of each dowel that creates a void in the slab to
accommodate the dowel as the adjacent slab closes the expansion
joint, as shown in Figure 2.
3.1.10