Askov American. [volume] (Askov, Pine County, Minn.) 1914-current, 1916-02-24

BUILDING A SECTION OF CHEVY GHAsR
ROAD.
dretis Of practical road builders from
all parts Of the country have inspected
II from time 10 time aud have mar
veled 1t the excellence of the work.
Manufacturers who have supplied
bituminutis materials for the treat
ment of the road have detached their
special experts for this service, and
the traffic over the roud has demon
strated under carefully observed cen
ditions the relative value OF the several
types Of road making up this great
highway.
The Chevy Chase road il experiment
al 1t consists of different types OF
ment-~bituminous macadam laid
by the penetration method, surface
treatments of waterbound macadam.
asphaltic surfaces On concrete founda
tions. bituminous surfaced concrete.
plain and oil cement concrete ana Wit
rifcd brick, all OF which are under
daily observation by expert road build
ers to ascertain which of the types Is
hest suited to the trat fic and which Is
condemned by practical test under the
same conditions OF climate. soil. rain
fall. heat and cold and like traffic re
quirements. 1t would he just the same
to the office of public roads which has
written this open book in concrete.
brick and stone whether any part of
il or all parts of Ii should fail. fail
In materials used. in constructions in
durability. In cost, in maintenance,
Road building Is u science now, and
efficiency is the only test of quality
In the stones used In the construction
of the Chevy Chase road, their specific
gravity, their weight per cubic foot,
their water absorption, their percent
age OF wear, their hardness aud tough,
ness are all determined by the most
careful scientific tests. ratrolmen are
constantly employed ON this road To
keep account of whatever defects in
materials aud construction may devel
op aud exact data as to the cost of
maintenance.
In one of the experiments covering
1851 square yards the cost ler square
yard for two and one-half inch btu
minous wearing surface was 10 Is
cents, This experiment. was made In
1911. For the maintenance of surface
there was no expense i'm the following
two years. but i'm 1914 this expense
was S7aTu
On another section of the road the
cost per square yard for two aud one
haf-inch hituminous wearing surface
was 64.42 cents and for supplementary
construction 1870 cents. This expert
ment covered an area of Ia5 square
yards, and in the three years from 1912
to ial4 Inclusive there MAS Ito expense
for maintenance
All surfaces ON this road were built
OF a uniform thickness of eight inches
and Of total width of nineteen feet
The base course was of stone ranging
in size from one to three inches, spread
to depth Of FIVE inches, the voids be-
ing filled with screenings, The wear,
Ing course consisted of stone ranging
from one to two inches generally. aud
upon this course the hitumen was ap~
piled In two applications of approx
mately one and oae-hatf TO one~half
gallon respectively, The cost of the
stone used In the foundation and wear,
ing courses varied according to the ex-
nense of uuarrsins and delivery. as 1t
would vary at all ether points. and of
all the materials OF construction and
charges for maintenance exact aeeoun.
has been kept,