The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1904-07-06
ROADMAKlNG,

Work Of Constructie, Supplemented by
Lectures by an Expert.
Several weeks ago the department OF
agriculture began its first experiment
in roadbuilding at New Brunswick,
N. j., under the direction OF 4. b.
Harrison, special agent of the Office OF
road inquiry.
The model road being considered is
the first Of several which the govern
ment is to build at the various expert
ment stations throughout the country.
The government furnishes q rock crush
or, screen, engine to drive steam roller,
spreading wagon and road grading ma
chine and two skilled operators. The
CITY furnishes the material, carts and
laborers.
The road will be Of macadam pattern.
An inferior grade Of traprock is found
In abundance neal New Brunswick and
this is being used in the substruoture
of the road. The superstructure is OBJ.
tanned from the traprock deposits in
the n~eighborhood Of Plainfeld and the
Oranges.
The model pavement will have a
depth Of about nine inches and the foun-
dation be made Of small, wedge shaped,
broken stones Of as nearly the same di-
mansions as possible. The roadbed will
be prepared by thoroughly rolling with
q steam roller weighing about ten tons.
Every hole will be carefully filed with
the same material that composes the
rest of the roadbed, and the finished
cross section will be formed by two
grades Of one foot in 80 feet from the
sides, uniting at the center, with the
apex slightly rounded Four inches OF
crushed stone will be spread on the
carefully prepared roadbed to form the
| foundation of the s~ubstructure. The
largest Of these stones will be crushed
30 fine as to be able to easily pass
through a two inch ring, and the small
est will be about half an inch in diam
eter.
This foundation will then be sprin'
killed., making The stone as wet as posi-
BILE without softening the roadbed, and
the roller passed over it a few times
until the stone is only slightly disturbed
by the teams returning with the empty
carts. The first foundation is not made
deeper than four inches, because 1t has
been found that a greater thickness
causes the stones to "elbow''' together,
wearing off their sharp corners, making
the "bonding," which is the great de.
sideratum, a very slow process, II not
an i~mpossibility.
When the first foundation has been
thoroughly sprinkled, a second coat OF
similar stone three inches in thickness
will be applied. After the stone haf
been we'll "bonded" to this extentit will
again be sprinkled, and while very wet
q thin coating Of traprock screenings
will be most carefully spread over the
surface, just thick enough to fill the
small spaces between the stones. The
size of the stones Of this last applica'
ton, which is called in the parlance Of
r%oadbuilding the "binder," will be
from half an inch in diameter to the
finest dust. When the work has reached
this stage, it will be left untouched II
the dry state as long as practicable te
harden and bind. The application Of
water and the passage of vehicles viii
be prevented as long as practicable.
As the work progresses Mr.. E. B.
Harrison, who is directing the work fol
the department of agriculture, will de-
liver lectures explaining the process o:
laying the road. Rutgers college stu
dents in the agricultural department
and farmers will be invited to attend
the lectures and witness the work.