Devils Lake inter-ocean. (Devils Lake, N.D.) 1909-1915, 1912-04-12
Roadlllla lfiin il I
North DakOta.
By II 7 Hard, eoiosist
North Dakota Agricultural
College. .ss.. ,I5..sj

by II. Hard, Geoiogist,
), North Dakota Agricultural Z
I. College. S. $
= !. i. i. !. j. !. \.
While in one sense OF the word
North Dakota may be poor in road
making rock, on the other hand, she
Is exceptionally fortunate in having
thousands Of miles Of natural sand
clay roads Of low gradient. ss;3fl +
Nature has generously deposited in
the central two-thirds Of the state clay
saturated with sand, or SO nearly so,
that it requires but a small per cent
to be added to make it SO. Sand clay
roads are the coming roads Little is
known of artificially constructed ones
In North Dakota, but as a matter Of
fact we are using many miles Of those
nature has made rs 8 f sss: 9ss sss5S
Z In the experience of the federal ex-
perts, and Of the local authorities in
many places, especially in the South,
the sand clay road construction Is be-
yond the experimental stage. They
have proven great success and in
the South are for some purposes con-
sidered superior to macadam.
II an obstruction equal to 4 per cent
Of the wheel radius increases draft
over twofold 1t is imperative that ad-
vantage be taken of every available
road material resource: A concrete
example Of the resistance Of poor
roads is seen In that an obstacle 0.9
Inches high Is 4 per cent of the radius
Of forty-eight-inch wheel, or In other
words, an ordinary wheel blowing up
q one-ineh rut more thanadoubles Its
draft. II. The geologist leaves to the
engineer the development Of such
vital problems, as well as such facts
as that a given force pulling four tons
on macadam pulls hut one ton or less
on muddy road Where rocks for mac
adam are lacking sand clay offers q
cheap substitute and reduces the draft
to one-third Of even one-fourth Of what
It Is on the average earth road, as
careful time. tests show. M 5S5
4 In initial cost the sand clay road APP
peals most strongly, being on the aV-
GRACE about one-sixth of that Of mac
adam. Many such roads cost about s
cents per square yard, or $500 to $500
Per mile, as against $1,000 to Sc, 900,
depending on amount of stone added
and many, other factors, in the mac
adam type. y i. Z, 4 NJ. II sEs5; 5jss3 !.
The principle Of the sand clay Is
I. simply that of adding either clay or
sand to the graded roadbed, deficient
In either, until the sand Is at the point
I; called saturation, which is explained
as being in the state where the angu.
lar sand particles are abundant enough
to readily touch and give bearing sur
faces when worked under wheel and
hoof Simple experiments can deter.
mine this correct mixture, which any.
lone can work out. The sand must be
. sharp and angular, as rounded grains
slip over one another and make poor
I bed. Again, the clay content must be
great enough to fill the ,voids between
! the sand and act as binding materi:
/ al. The problem in such heavy clay
soil areas as the Red River valley IL
] simpler than in very sandy areas, az
! It is naturally cheaper to handle sand
!, IL applying it to clay soil than to add
clay to a sand soil Pudding or init
] mate mixing OF the two substances
4 must follow. This is sometimes done
4 sarti6cially at considerable expense ol
4 may beHleft for travel TO accomplish
j Where the natural road site fconsti
tutes the bulk Of the constructive ma
fteriaI, the question of material and
I method of making are not easily sep
arabic, AS a concrete example offcla,
! sand road construction may refer tt
] one case where to sand road wal
4 added nine to twelve inches of clay
i to this two inches of sand was. added
! and mixed in by travel This mixing
i BY travel is slow, taking about a veal
Z for completion, but eliminates the ex
q penSfYe process with ploW and grader