The Logan Republican. [volume] (Logan, Utah) 1902-1924, 1916-09-12
Sand.C|ay And
Gravel Roads And
Their Construction
BY Manen Allen


years will pass before we shall be
able to design, build, and use each
SO as to secure the best results. The
types that are in general use are,
earth, sand clay. gravel, macadam,
concrete and block.
The sand clay road is made use OF
where the materials are available
for this type. Like the earth road It
will not stand up under heavy traffic
through either prolonged dry spell
or prolonged wet spell. It is a lit.
! tie more durable however, than the
earth road, but not SO good as we'll
built gravel road. The same precau.
tons in the matter Of drainage should
be taken as in the case of the earth
road. All types are alike in this re.
gard. and in order to secure the best
results, thoroughly drainage must
first be provided. The said clay road
is one composed Of combination in
the proportions Of one part Of clay
and three parts Of sand. The proper.
lions must be varied to fit the char.
acter Of the materials. Usually the
best clay to use is that which is the
stickiest, and graded sand is usual.
ly better than sand or uniform sized
grains and sharp sand Is. better than
sand OF round grains. The sand and
clay are first mixed dry to secure
uniform mixture. 1t is then thorough
ly wetted either by sprinkling or
rain, mixed again, shaped by the road
grader, rolled, and put into finished
shape by the drag. The mixing is
usually done by harrow and disk
harrow followed by straight or a
spike tooth harrow gives good re.
suits. The crown Of completed
sand clay road should be about three
quarters OF an inch to the foot. Much
better results will be obtained IL the
subgrade Is thoroughly consolidated
by rolling before placing the sand
clay mixture. This is true OF any
type Of road, even that of earth. II
is not possible by ordinary methods
OF rolling to consolidate thickness
OF more than about five to six inch.
es OF material at a time.
The maintenance of the sand clay
road Is performed in the same man.
ner as for the earth road, except that
for some time after construction the
surface must be carefully inspected
to determine whether the proper pro
portions of sand and clay were used
or the mixing well done. II there az,
pears to be a surplus Of sand on the
surface, It should receive a thin GOV.
ering of dry clay, and, If sticky. a
little coarse sand should be uniform
ly applied. The cost of maintaining
a sand clay road should not exceed
that Of an earth road.
In many localities gravel is abun.
dant and may be used to advantage
in road construction. For moderate
traffic, the gravel road gives excel.
lent results. The gravel for the pur.
pose should be hard and tough and
contain approximately Is per cent Of
binding material in the shape OF lime,
clay, CT loan, the preference being
In the order given. The gravel should
no hu
rounded or spherical and for this rea.
son pit gravel Is usually superior to
creek or river gravel. Pit gravel will
usually contain a larger proportion OF
binding material than stream grave.
satisfactory results are difficult to
obtain without screening. The per-
centage of fine material is quite Of
ten excessive in gravel deposits and
unless screened road formed OF 1t
will be likely to break up in spots.
The gravel road should be construct
ed in two courses. The bottom course
should be about six inches in thick
ness after consolidation, and for 1t
the larger sizes used, from IL to
2 IL inches. This should be evenly
spread, rolled, filed with finer ma
terial containing about 10 por cent
of binding material, and rolled until
solid, after which the top course of
about four inches should be put on.
The top course should be composed
OF material from "a to Ia inches.
It should be rolled lightly at first,
then filed with fine material contain
ing amout Is per cent of binding ma
terial, rolled, sprinkled, and rolled
again, until solid and with all voids
Hlled. After the road has been well
consolidated, 1t should be covered
with thin layer Of course sand, at
ter which 1t is ready for traffic. 1t
Is fully as important to Ioll the sub
grade for a gravel road as for an
a.-th a,,A ~