La Junta tribune., 1912-06-22


tained from streams Is usually Inferior
10 pit gravel Tor the reason that the ac-
ton OF the water has worn tie pebbles
smooth aud practically all the nne
binding material has been removed by
the same agency. Even II clay or loan
II mixed with river or creek gravel the
result In not likely to be as satIsfact0ry
n that Obtained by the use Of pit gr.v-
el PIT gravel frequently contains too
much clay or earthly matter. while river
gravel may have too much sand lu
such cases II Il sometimes advisable to
screen the gravel ~ as to eliminate the
material which il too fine or that which
Is too cOarse. The screen should be
similar to that which IL used In pre-
pairing material for a m.cadnm road.
In the handling OF the gravel care
should be exercised not to separate the
binding material from II. nor should
this binding material be allowed to
settle to the bottom In spreading tho
material over the road surface. II
will often be found advisable to spread
q thin layer Of such binding material
over the surface after the material has
been distributed and rolled. aud after
this the surface should be spriukied
and rolled again or else rolled while
still damp from the rains.
A large part Of the gravel found in
the Atlantic coastal plane is sufiicient.
ly nne and uniform to render unneces.
sary any asserting for road building
purposes. but when the gravel. expe-
ctally that which = to constitute tho
surface layer. contains large pebbles
these should be removed and either
thrown aside or else raked into the
foundation or recrushsyi. Al least 10
per cent by weight Of the gravel should
be pebbles above one e-eighth inch In
size. aud there should te no pebbles In
the bottom layer that will not pass
through two and n half or three inch
ring. and In the top layer there should
lie no pebbles which will not pass
through one and onc-half inch ring
Not over ~ per cent Of tn. mass
should lie clay. and this should be uni
formly mixed and should contain no
large Jumps. Ten or Il per cent Of clay
produces better results than ~ per cent
II the foundation or rpadied is loose
II should be carefully rolled 1t is
quite as important to have solid
foundation for n gravel road "a for n
macndam road Gravel VIII compact
TO about ~ per cent Of Its depth. loose
measure. provided earth shoulders are
placed on both sides OF the road To
prevent the wasting away of the
gravel on the sides II gravel IL nbun.
dnnf. however. these shoulders may De
built of gravel Instead Of with earth. 4
or the road may Ice surfaced with
gravel from shoulder TO shoulder n
the compacte'i depth OF the gravel {
road Is to ,e rirh, inches and the
width twelve fee; II will take abeut I
> 30 cubic yards OF gravel to the mile. |
and Il l. best to make the first layer
about six inches In depth. loose meas
ure. and the second layer about four |
inches In depth. loose measure
Gravel should not ,,e dumped direct !
iy on the rond. rs this viii usually re-
suit In rough. uneven surface II |
specially devised spreading wagons |
nrc not used the gravel should lr
iumfssi on boards and sIrend from
them on 10 the road
The grnvcl should be placed on TIN.
road commencing NJ the end nearest |
the grnv"l pit. In order that the teams |
will aid In packing the material. \
spike or tooth harrow mny be usei To |
advantage In spreading the materinI. |
but II the gravel contains only n small |
amount Of binding material the hnr-
row should not hc used. as It will have |
the effect Of bringing the larger peb.
blcs "a the surface and shaking tn. |
binding material to the bottom.
Each layer of gravel should bc rolled |
The rolling should begin |
at the sides AMI continue toward the
.-.n'cr until tn. surface is thoroughly
The surface layer should