The diamond drill., 1918-04-27
NO MORE WATER
BOUND ROADS
IRON CO. HAS TURNED TO BTU
hiIN0US CONCRETE
SEEK PARMENT METAL TOP
Water Bound Macadam and Gravel
Roads Will Not Last Under The
Great Traffic Demand

Iron county, which was among the
first counties in the upper peninsula
TO enter the good road movement
when the automobile came into gen.
eral use, has practically decided TO
turn to bituminous concrete as the
permanent type OF road construction
hereafter 10 be used.
Tile first work OF the kind will be
the two miles OF new construction on
the north and south trunk line, con-
tract for which was let last week To
Herman Holmes. A great deal viii
depend upon the success attained in
this work as TO future efforts in that
line.
The Penetration Method.
The most economical method OF
building a bituminous concrete road
is by what is known as the penetra-
tion method. BY this method the bind
er. trivia or other tar compound, Is
sprinkled upon the freshly spread
rock and let penetrate into the open
ing between the rocks which are filed
with finer rock and screenings and
rolled into a compact mass.
The binder oil Is put on hot and
the whole mass is rolled into shape
while the tar on the rocks Is still
warm. When IL cools and sets the
rocks are firmly bound and no dust
is sucked up by passing autos TO be
blown away and thus disintegrate the
road
Only the top two or three inches
are treated in this manner. The bot
tom course Is OF rocks firmly bound
into place by rolling Just as Is done
with water-bound macadam. On the
two miles that Iron county will build
this year the binder coat will be Pa
inches In thickness.
The tar holds the rocks together.
or better holds the small rocks and
screening with which the larger rocks
are keyed into place, whereas, with
water-bound macadam the road dries
and the fine rock and screenings are
sucked up by the auto tires and blows
away thus leaving the larger rocks
uncovered, and sooner or later the
binder having been removed these
| larger rocks begin to move. This
process Of tearing out the binder ma
terial on water-bound macadam is
called rayelling.
Extra Cost Is Not Great.
The extra cost OF building this
! kind OF road IL not much greater than
/ Is the building OF water-bound macad-
am. The extra cost Genes mainly I'm
| the purchase Of the oil and heating OF
I the same. The making OF water
bound macadam calls for the sprink-
1 ling OF the rock with water and.
whereas frequent sprinklings are ne
/ cessary with water-bound roads only
one or two sprinklings are necessary
with a taryia bound road Thus, the
labor OF applying the tarvia Is not
any greater than is the applying OF
4 the water.
The matchmaking OF a water
] bound road requires great deal or
rolling, but with tarvia- bound ma
cadam only comparatively small
amount OF rolling is required as the
stun binds quickly The difference I'm
rolling costs will easily compensate
for tile extra costs or heating and
applying the tarvia so that when the
proportion Is trimmed down to It's
lowest point the extra cost is just
about the cost OF the tGrvia.
Iully Road Next Year.
III the venture is success. and IL
Is confidently expected that IL Will
be. the next piece or road built In this
manner will be the Tully road, that
section lying between the Chicogan
creek bridge and Mapleton on the
road between Crystal Falls and Iron
River After that the spots on the
present stretch that Will give out each
In turn be resurfaced in this manner
so that I'm a comparatively few years
tho entire trunk line between Crystal
Falls and Iron River will be OF a BIZ
luminous macadam construction
The Tully road will reed resurfac-
ing next year The commission talked
some OF working az II this year as N
Is quite rough. but Il WAS finally de-
cided TO make the experiment on the
Amasa trunk this year and get well
Informed upon costs. methods and
durability and then the commission
VIII be In better shape 10 INTELLIGENT
ly apply this surface or some other.
TO the trunk line between the two cen.
ters OF population In Iron county.
Government Adopts Method.
The United States government has
recently adopted the btuminous con-
crete road for resurfacing In France
The three battalions OF the 10Th en-
gineers which viii be devoted 10 road
building IN France will spend most,
OF their time resurfacing the French
roads which have become badly worn
and Captain Burridge recently In.
formed us that the resurfacing viii
all be done with bituminous concrete
II u quite probable that the mixing
method instead OF the penetration
method will be employed In France as