[Amended 12-11-1951 by G.O. No. 46-1951]
For secondary streets, the following types of pavement are hereby
prescribed, approved and adopted, both pavements to be in accordance
with the requirements set forth in this article:
A.
Preparation of subgrade. The subgrade of the roadway shall be prepared
for the pavement by being dressed to the proper shape and to a grade
parallel to the finished grade of the street and four inches below
the same. All holes shall be properly filled with suitable, sound
material, inequalities of surface shall be leveled, and all unsuitable
material shall be removed. When thus prepared, the surface shall be
thoroughly rolled with a ten-ton roller to the satisfaction of the
Commissioner of Public Works.
B.
One-and-one-half-inch trap rock. On the subgrade prepared as above
shall be laid a layer of one-and-one-half-inch crushed trap rock spread
by means of an approved road grader equipped with a blade to such
a depth that, after the application of the bituminous material, three-fourths-inch
and three-eighths-inch trap rock hereinafter specified, the compacted
pavement will be four inches in thickness with a finished surface
conforming to the finished grade of the street. The stone thus spread
shall not be filled but shall be keyed together thoroughly by rolling
with a ten-ton roller. The surface shall be left smooth and of firm
texture, clean and free from dirt, clay or other material which would
prevent the easy penetration of the asphalt cement. If any stone spread
for this course becomes wet, it must be allowed to dry for the full
depth of the course before the pouring of the asphalt cement proceeds.
C.
First coat of asphalt cement. The approved asphalt cement heated
to a temperature of not less than 275° F. and not more than
350° F. at the time of application shall be applied uniformly
on the surface when dry to the amount of not less than two gallons
to the square yard.
D.
Three-fourths-inch trap rock. Three-fourths-inch crushed trap rock
without dust shall be spread over the surface by means of an approved
mechanical device in such quantity as to completely fill the voids
in the larger stone. This course shall then be rolled firm. The rolling
shall be continued, adding additional broken stone, if necessary,
until the course of stone is thoroughly compacted and its surface
is true and even.
E.
Seal coat of asphalt cement and three-eighths-inch trap rock.
(1)
After the three-fourths-inch stone is rolled to the satisfaction
of the Engineer, all loose stone shall be swept from the surface.
Asphalt cement for this coat shall be the same as for the first coat
and shall be applied at the rate of one gallon to the square yard,
heated as above. The surface shall then be covered with three-eighths-inch
trap rock and rolled until compacted. The rolling shall proceed continuously
until all roller marks are eliminated and no further compression is
possible. A sufficient amount of three-eighths-inch stone shall be
left on the surface to protect the road while setting up.
(2)
The asphalt cement shall be refined asphalt, of a combination of
refined asphalt and flux of suitable consistency for use in paving
by the penetration method. The probability is that New York State
Specifications Item 64P with penetration limits between 100 and 120
will be called for.
(3)
For applying the asphalt cement, an approved pressure distributor
shall be used with a pressure of 50 pounds per square inch or more
as the Engineer may direct.
(4)
All tanks and trucks for asphalt cement delivery shall be equipped
with suitable gauges and charts, properly certified, so that the quantities
actually delivered and applied can be readily and accurately determined.
The quantity of asphalt cement will be determined on the basis of
the number of gallons used at 60° F.
