The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1903-02-25
ROAOMAKING.


yverh a c~onstrsetisn Supplemented b.
Lectures By IN Expert.
Several weeks ago the department OF
agriculture began its first experiment
In roadbuilding at New Brunswick.
N. J., under the direction Of e. B.
Harrison, special agent Of the oeice Of
soad inquiry.
The model road being considered 10
the first Of several which the govern.
.nent 10 to build ut 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 an, two skilled operators The
city 1neaAhes the material. carts and
lAboreraL
The road will be Of macadam pattern.
An inferior grade Of traprock Is found
in abundance near New Brunswick and
this In being used In the s%ubstructure
Of tho road. The superstructure IL OBJ.
tanned from the traprock deposits in
the neighborhood Of Plainaeld and the
Oranges.
The model pavement will have .
depth Of about nine inches and tho four-
datiou bs made Of small, wedge shaped,
broken stones Of ss nearly the same d.
mersions - 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 tho
apex slightly rounded. Four inches Of
crushed stone will be spread ON the
carefully prepared roadbed to form tho
foundation Of the s~ubstructure. The
largest Of these stones will be crushed
10 hne 90 to Be able TO easily pass
through q two inch ring, and the small.
ess VIII be about half an inch in diam
eter.
This foundation will then be sprin-
kled, making The Stone On wet as posst-
bio without softening the soadbed. and
tho roller passed over IL Q few times
until tho stone Ia only slightly disturbed
BY the teams returning with the empty
carta The first foundation 10 not made
deeper than four inches, because 1t has
been found that q greater thickness
causes the stones to ''elbow" together,
wearing Oh their sharp corners, making
the ''bondinG which il the great de-
sideratum, o very allow process. It not
IN impoadbility.
When the first foundation has been
thoroughly sprinkled, o second coat OF
similar stone three inches In thickness
will be applied. After the stone has
bean well bonded to this extent It will
again be sprinkled, and while very wet
0 thin coating If traprock screenings
viii be most carefully spread over the
surface, Just thick enough to I'LL the
small spaces between the stones. The
size Of the stones Of this last applica.
ton, which 10 called In the parlancs Of
roadbuilding the ''bindeg," will be
from half an inch In diameter to the
finest dust When the work has reached
this stage, IL win be left untouched In
the dry state az long as practicable to
harden and bind. The application Of
water and the passage Of vehicles will
b prevented ~ long rs practicable.
A. the work progresses MI. E. B.
Harrison, who il directing the work for
the department Of agriculture, will do
liver lectures explaining the process OF
laying the road. Rutgers college stu.
dents In the agricultural department
and farmers will be invited to attend
he lectures and witness the work.