The daily telegram. [volume] (Clarksburg, W. Va.) 1901-1926, 1912-06-07

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successive edttiedtioh 81 tls9soii, and
If this soil Is used in tie construction
Of road lis Clown as. stop.s III road.p
There are maiy varieties 81 clay and
consequently a5Eide yafiattop in the
chaFact eristies fSpi ~ sand Clay road.
The quality Of the sand Is asyariable
factor, as 1t may range dill the way
froIp fine, dust fticles to coarse
grains and gravel and may be perfect.
" clean or mixed with loamt and other
mat eridt. In c8nsed Genee OF these wide
differences In The materials constitpt-
ing sand-clay roads it is imp6ssi hle to
.niatntaina Uniform standdfd as to
quality of the road or methods of con.
struc1on.
Not all but most sand consists OF
| tiny grains OF quartz. While quartz
is enc OF the hardest minerals known,
II Possesses practically no binding or
eelnentingS power. The grains of sand.
.insegd 6f aeohering in a tough mass
llIlasrs the anaSt of traffic ard the &C.
ti8tl of.ygtI ten remain loose gnd shift.
Ing vie sand when dry Is easily
displaced ~ sthe wind which pro,
duees inatitts ysay the ever shifting
sand hlllss Nnrpad is so difficult to
travel as one. through fine sand.
If clay has been carried in small
quantities bys=Tnnning water and de.
posted as sediment it is known as
"sedlmentary clay" II the feldspathic
rock hasibeen. disintegrated in place by
water the clay is known. as residual
clay" The sedimentary clay. having
been carried in the form of fine par.
ticles, is finer grained than the residual
clay and is more sticky. and plastic.
In contrast with sand. Which possesses
no pi8amS power, but is v91y hard,
clay Is, ap0werful binder but does not
possess the quality of hardness. It Is
evident TINT in the construction Of a
sand-clay road the important property
in the clay is It's ,plasttrity oritendency
to become sticky and elastic when
mixed With Spater. The ctays which
IRE most plastic are called .!ball
clays." Another important property
Which is. possessed by elays Is widely
varying degrees Is the porosity or Gu
paeity for rapid absorption Of water
Clays which possess this quality in
the highest degree fall to pieces under
the action of water. These clays
are called shaking clays." twill read
lily be seen that the plastic or ,ball clays
will form apbetter and more powerful
binder for ssand-clay roads than will
the stalking ciays: but. on the other
hand, they win be much more difficult
TO mix, as they distntegrate with far
less rapiaity.
The shrinkage Of clay is an impor.
tant characteristic In connection with
the building Of roads. When. water is
mixed with clay expansion results, and
when the water evaporates the clay
contracts. This characteristic of ey,
pansion is much more pronounced in
some clays than in others, and it must
be apparent that the clays which ex-
pand the least are preferable for road
Building.
The theory of the sandcIay road Is
very similar to the theory of the mac.
adam road. In the latter rock dust
and screenings gil the voids between
the angular fragments Of stone and
when wet serve as cement or binder.
The: grains OF sand may be likened to
the angular fragments of stone and
clay e the rock dust binder. In the
most successful sand,clay road just a
Sufficient amount Of clay is used to ill
the Totds between the grains Of sand.
IN this way the sand sustains the
wear while the clay serves as a