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

ar inserter.
On the first inserter project, I-90 at Janesville, an extensive
amount of grinding was performed, and the final project PSI was
only 3.6. Field inspection of this project revealed that,
especially in the southern portion of the project, some of the
existing roughness and grinding was related to the dowel bar
inserter. In some unground stretches, cyclical distortion of the
longitudinal profile was visually evident in synchronization with
the pavement joints. In some ground stretches, cyclical
variation of the depth of grinding was visually evident in
synchronization with the pavement joints. However, the overall
majority of roughness and grinding on the project appeared to be
related to longer wavelength profile distortion, which is
typically associated with other independent paving problems.
On the second inserter project, USH 18/151 from Dodgeville to
Mt. Horeb, a moderate amount of grinding was performed, and the
final project PSI was 4.2. Field inspection of this project
revealed that no significant amount of roughness or grinding was
synchronized with the pavement joints. The roughness and
grinding on this project appeared to be all related to longer
wavelength profile distortion, associated with other independent
paving problems.
Some roughness on this project may have been
caused by construction problems with the experimental open-graded
base course which was used on portions of the project.
On the third inserter project, the South Madison Beltline, a
relatively light amount of grinding was performed, and the final
project PSI was 4.6. With a PSI that high and the small amount
of grinding, there was not much initial roughness built into this
project. Field inspection revealed no significant profile
distortion associated with the joints. The limited grinding
which was done appeared to be related to longer wavelength
profile distortion, independent of the joints.
All three of these projects were paved by the same contractor.
It is evident that the contractor's ability to produce a smooth
riding pavement with this paver/dowel inserter combination has
improved dramatically. In conclusion, by the third project,
satisfactory performance was achieved with the dowel inserter
with respect to ride quality.
Voids: Another concern about the dowel inserter has been the
quality of consolidation of the concrete around the dowels when
they are inserted. Significant voids (dime-size or larger -
small bugholes were not counted) were found immediately above the
ends of 22% to 34% of the dowels on the inserter projects. The
voids were always very close to the ends of the dowel, within
about the last inch of the bar. On two of the basket projects,
no voids were found above the dowels, but on the STH 29 Vinton
project voids were found above 40% of the dowels.
With the inserter, the concrete flows upward past the dowel as
3.5.15