The ranch. [volume] (Seattle, Wash.) 1902-1914, 1912-05-01
USING CONCRETE ON THE FARM.
Continued from first page)

the concrete has set, freezing will
not cause it great injury, provided 1T
is not subjected to heavy pressure
before it thaws and has become harden
ed perfectly. Some users have used
fresh manure over newly made con-
crete to prevent it from freezing, but
it should always be remembered that
this will cause the surface OF the con-
crete to become soiled and stained.
So ESELECTlNG THE SAND.
Sand constitutes from one-third to
one-half of a concrete mixture and
should, therefore, be selected with
care. 1t should be lean and coarse.
The freer the sand is from loan, clays
or any vegetable matter the better
and stronger will be the concrete,
other things being equal. Coarse
sand does not require as much cement
as fine sand. The government has
found by repeated tests that an ex-
ceedingly fine sand requires seven
times the amount of cement required
by coarser sand retained on 2O-mesh
screen without increasing the strength
of the concrete. A mixture or coarse
and fine sand is best.
To determine the amount of loan,
clay or vegetable matter in SAND, I'LL
a fruit jaI about fourth full or the
sand and then fill nearly full of water.
Shake we'll and then allow the sand to
settle. If much clay or foreign
matter settles on top of the sand it
should not be used for concrete I'M
less it is washed.
SELECTING GRAVEL.
The same precaution used in select
ing the sand should be used in select
ing the gravel. All soft stone slate,
shaIe, etc., should be avoided. Wash
ed river gravel is usually very good.
Sometimes such gravel contains the
proper proportions Of sand and gravel
and may be used without being screen
ed. For the best work it is safer to
screen the gravel and then mix the
elements according to correct proper
tions.
In planning for a piece of concrete
work it must be rem EN- ered that the
total quantity of concrete will be-
very little more than the quantity of
gravel or broken stone that is used.
This is because the sand and cement
only fills the spaces between the
stones.
PROPORTIONS FOR DIFFERENT
WORK.
The proper proportions for different
kinds of work we give as follows from
Concrete, Plain and Reinforced.
"For reinforced engine or machine
foundations subject to vibrations; for
reinforced floors, beams and columns
for heavy loading, tanks and other
water tight work proportions 1:2:4,
that is, one barrel flour bags) packed
Portland cement las it comes from
the manufacturer to two barrels (7.6
cubic feet) loose sand, to four barrels
(l5.2 cubic feet) loose gravel or broken
stone.
sstor ordinary machine foundations,
thin foundation walls, building walls,
arches, ordinary floors, sidewalks and
sewers-proportiOn 1:2%:5.
"For heavy walls, retaining walls,
piers and abutmentS, which are to be
subjected to considerable strain-prO-
portions are 1876.
"For important work in masses
where the concrete is subjected tu
plain compressive strain, as in large
foundations supporting stationary
load, of backing for stone masonary-
proportions are Ia q. -
MIXING THE CONCRETE.
Concrete should be mixed on fiat.
water tight platform. The cement,
sand and gravel should all be measur-
ed as this is important. convenient
method of doing this is to use as a
unit of measurement box or barrel
70 ntIt mo N