Willmar tribune. [volume] (Willmar, Minn.) 1895-1931, 1901-03-27
TAR NACADAM PAVING.
lence, Durability and Cheapness
1t Has No Equal.

United States Consul F. NJ. Shepard,
at Hamilton, Ont, says:
''After years of experiment this city
is laying a pavement that for excel
lence, durability and cheapness is
commended for examination to those
in charge of similar work in the United
States. Thepossibility of making good
roads at reasonable cost has been
demonstrated, and tests extending
over number of years on business
streets prove that tarred macadam
makes not only a smooth and solid
roadway, but one that can be kept in
perfect repair at nominal expense.
The first cost in this city, where lime
stone is abundant and near at hand,
is from 70 to Sc cents per square yard,
and the engineer estimates the cost
of repairing on heavy traffic streets
at less than one cent per yard a year,
while asphalt costs over three cents.
The addition of tar renders the road
way impervious to water, frost-proof
in winter and prevents mud and dust
in summer. It is easily repaired and
does not require scraping, thus avoid
ing much wearing of the surface.
Zone block of tar macadam laid
more than a year ago on a business
street where there is heavy teaming
shows no perceptible wear to-day. In
residential streets these pavements
have been in use eight years without
any repairs, and are still in good con-
dition. The success of this method
of roadmaking depends on care in its
execution, as in the case of all COM
posite work of this character, and l
submit for the information of those
interested the substance of an inter-
view with the engineer of public
works, E. G. Barrow, covering details
of the processes in use here. Either
stone or cement curbing should be
placed before beginning the roadway.
Cement costs here so cents per 1ineal
foot and is six inches thick and 20
inches in depth and laid on broken
stone or gravel. Corners are rounded
and an iron plate imbedded for pro-
lection. On business streets stone is
preferable.
"An essential in roadmaking is .
hard and compact foundation, which
can be secured only by the liberal use
of heavy rollers (12 to 16 tons) while
the base is being prepared. The grade
and Gambler should be so designed as
to carry water off the surface quickly
and all earth above the subgrade
should be removed so as to conform to
it's level-12 inches below the natural
surface-which subgrade should be
thoroughly rolled and soft spots filled
with stone. The foundation must be
compost, solid bed of stone not less
than six inches in thickness. If the
soil is of a spongy nature, large, fat
stones are preferred. All interstices
should be filled with small stone and
gravel well rolled in. Over this a coat.
ing of gravel should be rolled hard
and then a layer of tar-saturated
stone, not exceeding two inches in
diameter. These stones before being
mixed with boiling tar 30 to ~ i'm.
perial gallons to the cubic yard) must
be thoroughly dried, either in the sum.
mer sun or by exposure on heated
plates. until all moisture is expelled.
''After thorough rolling another
stratum or tarred stone of the same
dimensions and thickness is added.
rolled and covered with layer OF
gravel and quarry chips, also mixed
with tar, one inch in thickness, to be
rolled down from three-fourths to
one-half an inch. A top dressing OF
screenings is then added, and if light
color is desired it may be obtained by
adding cement. Most of the stone
used here is machine crushed."