Materials for the construction of concrete sidewalks
and curbs shall consist of the following:
A. Cement.
(1) Cement shall be true portland cement and shall meet
the requirements of the current Standard Specifications and Tests
for Portland Cement adopted by the American Society for Testing Materials.
(2) Cement shall be natural cement similar to that manufactured
at Rosendale, New York.
B. Fine aggregate. Fine aggregate shall consist of sand
having hard, strong, durable grains and shall be free from injurious
amounts of dust, lumps, soft or flaky particles, shale, alkali and
surface coatings and shall not contain injurious amounts of vegetable
or other organic matter. Fine aggregate shall range in size from fine
to coarse within the following limits:
(1) Passing through a No. 4 sieve, not less than 85%.
(2) Passing through a No. 50 sieve, not more than 30%.
C. Coarse aggregate. Coarse aggregate shall consist of
crushed stone, gravel or other approved inert material with similar
characteristics, or combinations thereof, having hard, strong, durable
particles free from injurious amounts of soft, friable, thin elongated
or laminated pieces, alkali or organic or other harmful matter. Coarse
aggregate shall range in size from fine to coarse within the following
limits:
(1) Passing through a one-inch sieve, not less than 95%.
(2) Passing through a No. 4 sieve, not more than 15%.
(3) Passing through a No. 8 sieve, not more than 5%.
D. Water. Water shall be clear and free from oil, acid,
alkali, organic matter or other deleterious substances. It shall preferably
be equal in all physical and chemical properties to potable water.
Materials for the construction of stone curbing
and sidewalks shall be as follows.
A. Stone used for flag sidewalks shall be not less than
two inches thick nor less than five feet wide, and each stone shall
contain at least 10 square feet. Stone shall be bluestone and of good
quality.
B. Stone for curb shall be not less than four inches
thick and a good grade of uniformity. The depth of the curb shall
be not less than 16 inches and the length of the stone shall be not
less than three feet.
C. All stone used in the construction of sidewalks and
curbing shall be approved by the Commissioner of Public Works.
The construction of concrete sidewalks and curbs
shall be as follows:
A. Sidewalk.
(1) The area to be occupied by the sidewalk shall be graded
five feet in width for entire length of the improvement. A foundation
four inches thick shall be placed, of clean gravel or broken stone
not over two inches in size, or clean, soft coal cinders, well tamped
or rolled.
(2) Frames of the same height as the thickness of the
walls shall be placed to outline the external edges of the walk and
set to conform to the established line and grade of the walk.
(3) Concrete shall be mixed in the following proportions
by volume:
(a)
One part portland and natural cement.
(b)
Two parts fine aggregate.
(c)
Four parts coarse aggregate.
(d)
Five bags of portland and one bag of natural
cement per cubic yard of concrete. Note: In lieu of the use of natural
cement, air-entraining cement or air-entraining agent such as pozzolith
added to the portland cement may be used. Any dispersing agent shall
be used in accordance with the manufacturer's instructions.
(4) Each concrete flagstone shall be five feet in width,
not more than five feet in length, and shall be four inches thick
throughout, except at driveways where the depth shall be increased
to six inches. The finished surface of the walk shall have a slope
of 1/4 inch per foot toward the curb. Each concrete flagstone shall
be separated from the next flagstone by a joint made with tarpaper,
and expansion joints 1/2 inch in width, filled with bituminous material,
shall be placed at intervals not greater than 50 feet.
(5) The wearing surface of the walk shall be finished
with a wooden float and lightly broomed. The exterior sides and joints
shall be finished smooth with a split float or split roller.
(6) When concrete walk is finished, it shall be kept covered
and moist for at least three days.
B. Curb.
(1) Concrete curb shall be the same mix as for sidewalks
and shall be five inches in thickness and at least 20 inches in depth,
and it shall be separated at five-foot intervals by installing premolded
expansion-jointing material, such as asphalt paper.
(2) The surface of the curb shall be edged and covered
for at least three days.
(3) Concrete shall not be mixed or placed when the temperature
is below 35° F. or conditions otherwise unfavorable for good work.
(4) Hand mixing shall be done on a watertight platform.
The cement and fine aggregate shall be first mixed thoroughly, then
the coarse aggregate added and again thoroughly mixed before any water
is added.
(5) Machine mixing shall be done in an approved batch
mixer which will ensure a uniform distribution of the materials throughout
the mass. The mixer shall be equipped with suitable charging hopper,
water storage and measuring device. The entire contents of the drum
shall be discharged before recharging. The mixing of each batch shall
continue not less than one minute after all the materials are in the
mixer, during which time the mixer shall rotate at a peripheral speed
of about 200 feet per minute. The volume of the mixed material per
batch shall not exceed the manufacturer's rated capacity of the mixer.
(6) Retempering of concrete is strictly forbidden.
The construction of stone flagging and curbing
shall be as follows:
A. The sidewalk shall be flagged with stone not less
than two inches thick, nor less than five feet wide, no stone to contain
less than 10 square feet. Said flag shall be well laid in sand or
fine gravel, on a grade and line on front edge of curb, and on an
ascending slant toward the inside of said walk of 1/4 inch to a foot.
The walk adjacent to the curb shall be two inches above the curb.
No joint is to be over three-eighths-inch opening.
B. The curbstone shall be free from taper and seams,
not less than four inches thick and as near uniform as possible, nor
less than 20 inches wide and three feet long, dressed on two faces,
the ends for a depth of one foot from the top to be truly squared
and dressed so that when laid the pieces shall abut truly against
each other, with joints not to exceed three-eighths-inch opening.
Such curb shall be set with proper inclination and well laid in fine
gravel or sand and on a bed of six inches of such material.
[Amended 11-24-1954; 5-28-1956; 9-24-1956]
A. Request for permission to construct ramps exceeding
20 feet in length shall be submitted to the Common Council for determination;
if the Council shall approve such a request, the project shall be
completed within 90 working days after such approval. Ramps under
20 feet in length may be constructed of either concrete or asphaltic
materials and shall extend no more than 24 inches from the curb, except
where the sidewalk is more than 24 inches from the curbing, then said
ramp may extend to the sidewalk. A gutter shall be formed along the
curbing by raising the ramp a minimum of two inches at this point.
[Amended 12-26-1956]
B. The Commissioner of Public Works may at his own discretion
permit the profile of the ramp and sidewalk section through a driveway
to be changed so that the curb side of the sidewalk may be lowered
as much as two inches, permitting better access to driveways.
[Added 3-11-1968]
C. Ramps heretofore and hereafter constructed in excess
of 20 feet in length shall be plainly marked with a painted white
line indicating the inside edge of the walk. Such white line shall
be painted approximately seven feet from the edge of the gutter or
on line with existing sidewalks, and for all purposes this will constitute
a regularly constructed sidewalk.
Grades for sidewalks and curbing will be established
and furnished by the Department of Public Works.
[Added 2-13-1979]
The dimensions for sidewalks as hereinbefore
set forth may be dispensed with upon application to the Commissioner
of Public Works for good cause shown where the strict compliance with
this article would create hardship or where a decrease in size would
be beneficial to the flow of vehicular traffic.