Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1912-05-03

produced 81 the front wheels and tia,
practically the entire disturbance OF
the road = produced BY the rear o.
driving wheels. II the effect were pro.
duced BY suction or vacuum the action
of both front and rear wheels should
Be somewhat similar at least, 1t seems
apparent 70 the writer, therefore, that
the road best adapted to- motor traffic
% the road which will best resist this
powerful tSactive shear. 1t has already
been demonstrated that no plain mac.
adam road = capable Of resisting this
force. &3sS sS z...s ALL. =:
II The, efforts Of progressive highway
engineers are thus directed primari.
u toward the preservation Of our stone
surfaced roads and the construction OF
dustless roads by the use of q binder
more powerful than stone dust and.
secondly. to minimizing or mitigating
the dust nuisance.
For the purpose Of discussing intelli-
gently the experiments thus far con-
Quoted with special binders the term
dust prevendves' has been applied
to all Of the various binders having for
their main object either suppression or
the prevention Of dust. These may be
divided into, two classes, temporary
and permanent The temporary binders
serve merely as palliatives and require
frequent renewal. The permanent bind
ers, so called, enter into the structure
of the road as constituent element
and are either incorporated with the
other materials at the time of the con-
struction or applied later by surface
treatment.
In the class Of temporary binders
may be included water. salt solutions.
light oils and tars and oil and tar
emulsfons. waste sulphite liquors, etc..
while the permanent binders include
the heavy petroleums and tars, pitches
and numerous oil, tar and asphalt prep
arations. The value of salt solutions,
which have been used to some extent,
lies in the Microscopic character of the
dissolved salt, which, having consider.
able affinity for water, keeps the road
surface in moist condition long after
a surface treated with water alone
would have become dry through evapo-
ration. ~
The light oils and tars as we'll as the
OIL and tar emulsions depend for their
eject upon a comparatively small
amount of true binding base left upon
the road surface after the volatile
products have evaporated. These ma
terials prove effective only so long as
they retain their binding power. When
the binding power is destroyed it is
necessary to apply more material.
The heavy oils and tars differ from
the lighter products in that they con-
tain a much greater amount of true
binding base. The results are, there.
fore, Of more lasting character and
hence the name permanent BINDERS"
The semisolid and solid preparations
usually contain a still greater amount
Of binder. With some few exceptions
all Of the true binders are bitumens.
The usual method Of applying these
to the road surface is by
uprinkling: The temporary binders can
usually be applied cold, but the perma-
nent binders because Of their much
greater viscosity must be heated until
fluid. In England and
France the use Of coal tar is practiced-
% large extent. and their methods Of
application have been highly developed.
Machines are in general use which are
'elf propelling and in which the tar is
heated and applied to the road surface
IL a spray under high pressure. These
70 called "tar sprayers" are not only
'ery economical in the use Of tar, but
insure a more even distribution and
,etter penetration of the road surface
han 1t is possible to obtain in almost
my other way.
In the construction Of dustless roads
be crucial question is that Of cost. The
fort must be to develop form of
obstruction which will Withstand fast
traffic and at the same time
. within the financial resources Of the
This Is largely being done
{ present by the use Of a bituminous
Under instead Of rock dust The two
Methods generally employed are known
4 the penetration and the mixing
In the former the hot liquid
Under is sprinkled or sprayed over the
tone and allowed to penetrate through