The subgrade on all types of road shall be properly
prepared after proper drainage has been provided. All boulders, muck,
quicksand, soft clay, spongy material and any other objectionable
material shall be removed as directed by the Town Engineer and Town
Superintendent of Highways. All spaces from which objectionable materials
have been removed shall be refilled with acceptable materials, such
as stone, slag or gravel, as directed.
After all drains have been satisfactorily completed
and the subgrade has been properly shaped, it shall be thoroughly
rolled and compacted with an approved self-propelled roller weighing
not less than 10 tons. Care shall be taken not to roll clay foundations
enough to develop a plastic condition. All hollows and depressions
which develop shall be filled with acceptable materials and the subgrade
shall again be rolled. This process of filling and rolling shall be
repeated until no depressions develop. In places where the character
of the material makes the use of such a roller impracticable, a lighter
one may be permitted. The subgrade shall not be muddy or otherwise
unsatisfactory when the pavement is placed upon it. All necessary
drainage to effectively drain the roadway must be completed before
the placing of any pavement will be permitted thereon.
Embankments shall be formed of suitable materials,
graded and rolled to the property lines, and approximately true to
lines and grades. All stones larger than three inches in diameter
or any other objectionable material shall be removed from the surface.
At all intersecting public highways, a smooth-riding
and satisfactory junction must be produced.
Curbs shall conform to the sections as shown
in the specifications, or of such sections as approved by the Engineer,
and shall be required only in streets and highways located within
an established storm sewer district; nor shall curbs be required on
streets and highways within existing storm sewer districts, which
are partially built up and improved and upon which no curbs have been
heretofore constructed. Cast-in-place curb under these specifications
shall be composed of Lake Erie sand, Lake Erie gravel, crushed stone
or crushed blast furnace slag. Blast furnace slag shall be as produced
by the Buffalo Slag Company.
A. Fine aggregate. The fine aggregate shall be washed
and graded in compliance with A.S.T.M. Specifications C3.3-49. It
shall pass the ten-cycle sodium sulfate test, with loss not greater
than 8%.
B. Coarse aggregate. The coarse aggregate shall be clean
and graded in compliance with ASTM Specifications C33-49 for nominated
size 3/4 inch to No. 4. It shall pass the ten-cycle sodium sulfate
test, with loss not greater than 5%.
C. Concrete strength requirement. Minimum compressive
strength on standard six-by-twelve-inch concrete cylinders shall not
be less than 3,500 pounds per square inch at 28 days.
D. At least two test cylinders shall be made on each
day that concrete is poured, one for seven days and one for 28 days.
Tests shall be made by a recognized testing laboratory satisfactory
to the Town Engineer. Cost of such testing is to be paid by the contractor
and included in his bid.
E. Concrete mix proportions (per cubic yard).
(1) Crushed stone or gravel concrete: portland cement,
(minimum) six sacks per yard; fine aggregate, 42%; coarse aggregate,
58%.
(2) Blast furnace slag concrete: portland cement, (minimum)
six sacks per yard; fine aggregate, 46%; coarse aggregate, 54%.
(3) Maximum slump for any of the three types of concrete
shall be six inches.
F. Cold-weather concrete. All concrete placed in cold
or freezing weather must have both mixing water and aggregates heated.
The concrete, when deposited in the forms, shall have a temperature
of at least 70° F., maximum temperature 110° F. After placing
concrete in the forms, it shall be fully protected from the elements
by being covered with straw or other suitable material for at least
10 days.
G. No concrete shall be placed on frozen ground.
H. Mixing and placing of concrete.
(1) Concrete may be either transit mix or job mix. In
either case the mix proportions must be held rigidly to those outlined
under concrete mix proportions of this specification.
(2) Care must be exercised in placing concrete in the
forms. After placing, it shall be rodded or spaded so that the finished
concrete shall be smooth and represent a workmanlike job.
(3) If, after removal of the forms, any open or rough
spots are noted, they shall be immediately repaired with a cement-sand
mix of 1:2 by the cement finisher.
I. Curbing shall be covered, immediately after finishing,
with burlap or other material acceptable to the Engineer. The cover
shall be kept wet for a period of three days.
J. The contractor shall protect the curbing and keep
it in first-class condition and alignment until the completion of
the contract. Any curbing which is damaged at any time previous to
the final acceptance of the work shall be removed and replaced with
satisfactory curbing at the contractor's expense.
K. Backfilling.
(1) All backfilling behind curb must be tamped in layers
not more than six inches in depth to a height of not less than six
inches below the top of the curb. Each earth layer shall be thoroughly
and uniformly compacted by solidly tamping with appropriate tools
in such a manner as not to injure or disturb the completed curb.
(2) All backfilling on the front, or pavement side, of
the curb shall be filled with crushed stone, slag or other suitable
porous material and properly compacted. No earth fill will be allowed.
No material shall be placed from October 15
to May 15 except by written permission of the Engineer, nor when the
air temperature in the shade is below 50° F.