The Dickinson press., 1914-04-04

improved and the resulting concrete
made stronger by the screening out
of some of the finer particles. So we
are fairly safe in saying of Dakota
sands that the coarser the sand the
better, other things being equal.
A very dirty sand, one containing
much clay or loan, should be used
with great caution, if at all. To de.
termine whether sand is dirty take
a quart Mason jar and fill about one.
third of sand, then to within an inch
or two Of the top with water. Shake
we'll until sand and water are thor
oughly mixed. Allow to settle for a
few minutes. The dirt will be found
on top Of the sand in a well marked
layer. BY the thickness Of this layer
the amount of dirt In the sand can
be roughly determined.
Sand Should Be Clean.
II. It becomes necessary to use sand
containing much dirt it may be wash.
ed and most Of the dirt removed.
This is rather expensive, however,
and it will usually be found cheaper
to get a cleaner sand, even IL the
first cost is more.
No definite rule a be given for
the proportion Of cement, sand and
gravel, as so much depends on the
kind Of sand and gravel. For ordi.
nary work, with fairly good sand and
gravel, n part (by measure) Of &C.
ment to two and one-half parts Of
sand to five parts Of gravel should
give a very good concrete. A fine
sand, or one with, much dirt in it,
will take much more cement to make
good concrete.
Mix Thoroughly. -,
After the sand and cement have
been thoroughly mixed together the
gravel should be added, then the wa
ter. Clean water should always be
used. Enough should be added SO
that when the concrete is shoveled in.
to place it will flow slightly, filling
all open places.
The following method has been
recommended by one Of the large ce.
ment manufacturers for determining
whether the materials to be used,
| and the proportions in which they are
to be used, are the proportions in
| which they are suitable: Mix up 8
batch Of the concrete, using the pro
portions and materials to be used
later in the real work and fill several
molds, six inches square and si1
INCHES deep. Keep these damp for a
week, at the end of that time remove
| the molds and strike the cubes with
a light hammer as If driving tacks; II
no indentation is made and the blocks
sound hard and are not broken under
medium hard blows Of the hammer the
mixture is at least a fairly good con
crete.
Concrete Should Set Slowly.
Fresh concrete should never be- ex
posed to the direct rays Of the sun
or to a hot wind. 1t is necessary that
1t. be kept moist until the chemical
actions, which produce the set, have
been completed. rs
Much good concrete work is spoiled
by allowing it to dry out too quickly
After It has hardened enough 80 that
the surface will not be marred dirt
may be thrown over it to keep il
moist. Do mot be afraid that it will
not set properly when wet. The worl
should be kept damp for a week OF
ten days; in hot weather It may be
~sprinkled thoroughly several times 9
day to good advantage
Among the many things which any
farmer. IL he uses care and good
judgment, can make Of concrete are
the following: Cellar floors, cisterns
tanks. feeding Adoors, barn floors
walks, fence posts, etc.
The department Of agriculture has
issued q very complete bHaletin on thu
manufacture OF concrete fence posts
which ID sent free 10 any one upoI
request. II shows the great advantage
OF these posts and tells, In detail
methods for their manufacture.