After completion of the rough grade and prior to the
laying of the foundation course, the subgrade shall be shaped to line and
grade and thoroughly compacted with an approved self-propelled roller weighing
not less than 10 tons. All hollows and depressions which develop under rolling
shall be filled with acceptable granular material and again rolled; this process
is to be continued until no depressions develop. The subgrade shall not be
muddy or otherwise unsatisfactory when the foundation course is laid upon
it.
Any soft or unstable portions of the subgrade which develop
under the roller shall be completely excavated and removed from the right-of-way
and shall be replaced with acceptable granular material and the area regraded
and compacted as above.
Before fine grading or construction of curbs and sidewalks
is started, all storm and sanitary sewers and all utilities, including house
connections and hydrants, shall have been installed and all fill and backfill
shall have been thoroughly compacted to the satisfaction of the Town Superintendent
of Highways and designated Town Engineer.
Fine grade shall conform to the prescribed width of pavement
and shall extend equidistant from the center line of the road right-of-way
and shall conform to the typical cross sections of the road pavement and to
the approved line and grade.
After the fine grade and all curbs have been constructed
to the satisfaction of the Town Superintendent of Highways and designated
Town Engineer, the developer shall furnish and place a foundation course of
approved run-of-bank gravel, crusher-run stone or crusher-run gravel to the
depths as called for in these specifications. All materials acceptable for
these courses shall be hard, durable and sound and shall be well graded from
course to fine. One hundred percent, by weight, of the particles shall be
of such size as will pass through a four-inch-square hole, not less than 30%
shall pass 1/4 inch, not more than 70% by weight, pass the No. 40 mesh sieve,
and not more than 10%, by weight, pass the No. 200 mesh sieve.
The materials shall be placed on the finished subgrade
by means of mechanical spreaders in three-inch layers and shall be thoroughly
compacted by rolling with a self-propelled ten-ton roller. Water shall be
added to the materials in such amounts as the Town Superintendent of Highways
and designated Town Engineer may consider necessary for proper compaction.
After compaction, the course shall be true to grade and cross sections, and
any depressions shall be eliminated by the use of additional granular materials,
thoroughly compacted so that it will not weave under the roller, and the total
depth after compaction shall not be less than 12 inches. The maximum particle
size permitted in the three-inch graded gravel shall not exceed such size
as will pass through a two-inch-square hole; 30% to 65%, by weight, shall
pass the one-fourth-inch-square sieve, and not more than 10%, by weight, shall
pass No. 200 mesh sieve.
The Town Highway Superintendent and designated Town Engineer may approve
and/or require the use of approved geotextile fabric and other materials where
warranted due to conditions of the subgrade.