Connecticut western news. [volume] (Salisbury, Litchfield Co., Conn.) 1871-1970, 1908-06-25
OF
CONCRETE BLOCKS
SOME PRACTICAL SUGGESTIONS

Soon Take the Place of Brick, Stone
and Wood in the Construction of
all Sorts of Buildings.
Inasmuch as there is a growing inter
est in concrete blocks for building con-
struction THE NEWS will present to its
readers, in two or three instailments, a
practical article on the manufacture and
and use of these blocks.
Many building experts declare that
the cement block will soon be in general
use in place of brick, stone or wood and
that the use of wood for the building of
even small residences will soon be largely
a thing of the past. ... ~
A building made from concrete blocks
is said to be practically indestructible.
while the cost is said to be much less
than for bricks. Then, again, with the
many fancy designs which it is possible
to give to the face of cement blocks
very handsome finish to the walls is
possible while all sorts of ornamental
mouldi2gs, panels and corners can be
provided for. Moreover, a kind of slab
for roofing, to take the place of slate is
now made from cement, so that every
part of the building can be made out of
this one material. /.-+ .sa
SPECIFICATIONS FOR HOLLOW BLOCKS.
Sand Such material as will pass
through screen -4mesh and is retained
in screen having mesh 1-64 of an inch.
This applies to river sand, bank sand or
screenings from q stone crusher.
@-5- GRAVEL.
Gravel-Such material, obtained either
from a bank or river, of such size as is
retained in screen having IA inch
mesh. 49,.
CRUSHED STONE. rr
Such stone from crusher as is re-
tanned in IA inch screen.
BANK GRAVEL. t. Il,
Such material as is obtained from a
pit or river containing both sand and
gravel.
AGGREGATE. ...
Any material, such as broken stone,
gravel or other fragments used with
cement and sand mortar in making con-
crete for the purpose of reducing the
cost and adding to the strength -'
VOIDS. s.-.....
The space existing between particles
which an aggregate is composed.
CEMENT.
Amy good quality of American or inn
ported Portland cement.
QUALITY OF SAND.
Sand suitable for concrete work must
not be finer than the above described,
must be sharp and gritty, not soft or
loamy, must be free from loan or. other
foreign material, and must not contain
any perceptible amount of clay or other
soluble matter. Some authorities con-
cede that clay to the extent of 10 per
cent in sand or gravel is not harmful.
This committee is of the opinion that
any perceptible amount of clay is I'M
safe. Crushed stone must be reasonably
free from dust, and must be retained on
the same sized screen as bank sand, viz
IA inch. Gravel or crushed stone must
be free from loan, dust or other foreign
material, and must contain no soft or
rotten stone.
DETERMINATION OF AMOUNT OF CEMENT
TO BE USED WITH AGGREGATE.
A theoretically correct concrete should
consist of sand and gravel, or crushed
stone, or a combination of them, contain
ing any amount of cement equal to the
voids in such combination. In other
words, interstices should be filled with
cement.
To state this in another way, if the
concrete is made up of sand and gravel
such proportion of cement should be
used with the sand as is equal TO the
voids in the sand, and such quantity of
this resulting mortar of sand and cement
should be used with the crushed stone
or gravel, as will fill all voids in the
fSRashed stone or gravel.
Restating this in a few words, the
cement should fill the voids in the sand,
and the resulting mortar should fill the
yoids ia the aggregate.
DETERMINATION OF vOIDS.
To determine the voids in the sand, or
the material to be used as an aggregate,
what is known as the water test" is
employed. In preparing for this test
the sand or gravel must be perfectly dry
Sand has greater volume when dry.
A receptacle holding known amour
such as quart jar, is filed with the
material to be tested, sand for example, !
and into this receptacle is poured as
much water as the sand or other ma
terial will absorb. The water should be
measured. The amount of water alb
sorbed indicates the voids and also in
dictates the exact amount of sand which
it is necessary to use in order to produce
a solid concrete.
ITO be continued