Frostburg mining journal., 1908-09-12
SURFAC|NG OF ROADS
An Excellent Foundation Is a
Prime Necessity.
MUST BE FREE FROM WATER
Provision Should Be Made For Thor
ou9h Drainase-How to Roll the
Foundation-Materia to Use For
Surfacing Rural Highways.

oush Drainase-How to Roll the
Observation-Disclosures to Use For
Surfaeins Rural Highways.
Before Il finishing surface of any
material is applied to a road all the
preliminary work should be cOmplet
ed The road should have been grad
ed drains provided and the road made
safe by proper guard rails. With all
this done, the dirt road is n founda-
ton for the different materials that
may be put upon 1t.
For country roads there need be
considered only pavements that are
put on In small fragments. The ma
terials most commonly used are gravel
and broken stone. Oyster shells and
Stag from iron furnaces are oftentimeS
employed in localities where these ma
terials are at hand, while under GER
tain conditions, when no other ma
terialS could be obtained. burnt clay
has proved serviceable. The object of
pavement is to furnish a wearing
surface for the road and a protection
for the foundation from water and con
seuuent softening 1t is in reality
roof.
When dry, all but the very sandy
soils are firm enough to support the
weight of wagons of all kinds, but
when wet little support is furnished
,h.N,,
fined will stand any pressure that can
be put upon it. Thus If n sandy road
bed is covered with a surfacing ma
/ terial which will hold the sand in place
an excellent foundation is obtained
While Il surfaciug material is designed
to take the wear, it is the foundation
that must resist the pressure, and any
road which is constructed without Civ
ing due attention to the foundation iS
wrong from the start and never wiz
be Il good road until the defect is rem
cdied. TO prepare natural roadbed
for Surfacng material 1t is necessary
to bring it to Il proper grade and to
conform its cross section with that OF
the finished surface that is, no sur
facing should be put upon roadbed
which is fiat or, as is oftentimes the
case. lower in the middle than at the
sides In such instances the proper
shape should be given to the rOadbed
by filling in with such material as is
necessary and then rolling the whole
until it becomes firm and unyielding.
During the course of construction of
roadbcd, if there are places that
have Il wet, springy SubSoil, they must
be drained and every precaution taken
to make the foundation of the road
dry. The pavement will keep water
from going through from the top, but
it will not keep water from percolatinS
into the foundation from springs ut
the sides or underneath. Therefore
where there is danger of water get
ting to the foundation from the sides
or from below it must be cut off eithe"
by side drains or by drains directly I'M
derneath the road itself. Where the
soil is too light, gravclly or sandy earth
should be cartcd in to take its place.
With the roAdbed brought up to
grade and provision made for thor
rolling either by horse or steam power
In the rolling of the foundation per-
hapS quite as good results can be OBJ
tanned with horse roller as with
steam roller. and i'll some loose soils
much less difficulty will he experienced.
although more rolling will he required
to compact the earth as firmly as by
the heavier steam roller. This is u
part of the work that is too often
sighted and is the cause of dcpreS-
sions subsequently appearing in the
finished road. The rolling of the foun-
dation will bring out the weaker
places, where there will be a settling.
The depreSSonS should he filled and
brought to an even surface with gray
el if it Is ut hand. 1t is cheaper TO
even up dcpreSSionS by rolling the
foundation than by attempting to
smooth the finished surface with addl-
tional broken stone. When the founda-
tion has been rolled and all unevenness
has disappeared 1t is then ready to re-
ceive the surfacing.
1t oftentimes happens when grading
particular piece of road preparatory
to surfacing it with broken stone that
1t Is necessary to do considerable
heavy filling. In such instances it may
be advisable to delay the laying Of
macadam for some time in order to
give the embankmentS time to settle,
for 1t is impossible to construct an EN-
bankment of earth more than few
feet In height without having subse
quent settlement. If this settling took
place evenly all along the embankment,
no particular harm would be done to
the surfacing Laid upon 1t, but owing
to the difference In the soils composing
embellishments and also the way the
earth is dumped there is always tend
ency for some parts to settle more than
others.
II there arise circumstances making
1t impracticable to wait for the en-
bankment to season" every precau-
tiOn should be taken In its formation
to guard against uneven settling. This
can be done by spreading the earth In
successive layers of about foot In
thickness, which are rolled or tamped
as solid as possible. Another advan-
tage in delaying the Surfacing OF q
newly graded road is that chance Is
given to observe the action under frost
Of certain sections and so provide ad-
ditional underdrain. which II omitted
might have caused failure In that
portion Of tba macadam.