The sun., 1908-12-13
as 70 HOUSES or CONCRETE
SOME POPULAR ERRORS ABOUT
TEE USE OF CEMENT.

TIilngs That Make Really Menolithio
Dwellings, Csstiy at Prosent-Their
Advantages Great, Tnough-Typcs
tho Pubic COnfuses with Concrete.
STeil man on the street. said en- en-
gineer, shat you are thinking Of building
q concrete house. and his answer will be
something like this: Don't be 20 foolish;
It's as ugly as sin. Why. out In Bogotha
they have put up bunohes OF concrete
houses for workmen ell alike, ell mud col-
ored limitations Of granite Or another
viii say: A friend Of mine made his house
Of concrete instead Of wood. and the fret
winter 1t ell peeled off,
sThe fact about these two typical an
swers that you will ordinarily get dis
paraging concrete is that neither the mud
oolored imitation of granite nor the house
that all peeled of the first winter was
built Of concrete: the first being so-cailed
concrete block house; the second cement
stuoco house.
There is no such thing as o conoreta
block. because no stone is used IN them.
They are cement mortar blocks.
'The trouble with these blocks hes
deeper than the fact that the block
machine promoters have put them pro-
misouously into ignorant and incompetent
hands. It lies In the fundamental fact
that In order TO make block on a machine
1t is necessary that the cement and sand
be exceedingly dry, that is. moistened with
very little water. 30 that they will be stun
enough to be removed from the moulds
Immediately. Good concrete or good
cement mortar must contain very large
percentage of water in order that the
capitalization OF the cement may properly
take place.
@As every one knows who has not been
led astray by tho careless use Of the word.
concrete is hard stonelike substance
composed. in varying proportions as Its
uses may demand. OF water, broken stone
or gravel. sand and cement. The nearest
approach in nature to concrete 10 found
in the old pudding stone. those round
tremendously hard boulders that we
find 30 often forming the rugged stone
walls Of New Englands farms.
Crack the pudding stone and you will
find 1t is seemingly q mass OF pebbles
Of varying size. from that OF grain OF
sand to an inch or 90 in diameter. all knit
together into q compact mass by some
oen,entitious substance. That Is ma
ture's concrete.
when concrete is used for building
construction it is almost invariably re-
enforced. and it il in the correct estimating
Of the size and placing of this reinforcing
steel that the science Of REINFORCED oon-
crete construction comes in.
| sWhile the use Of concrete goes 30 far
back into history that its origin is
unknown, the utilization Of steel as
reinforcement Of concrete is a compare
lively recent invention. This discovery is
credited to French gardener who CON-
ceived the happy idea Of putting a wire
Reinforcement into his cast cement NOR
tar flower pots in order to prevent them
from cracking. He found that his ex-
pertinent was 80 enormously successful
that he gave up his work as a gardener
to devote himself to the study Of reen-
forced 'concrete. Many OF the first re-
enforced concrete structures we're built
from his designs.
@The reason for this reinforcement is
easy for a layman to understand when
it is explained that concrete. like granite.
has enormous compressive strength. that
is to say, q column OF concrete will up
hold very great weight. but concrete Is
weak In tensile or pulling and bending
strength. When steel rods are correctly
placed and properly embedded in con-
crete beam they will take up all the bend
ing and shearing stresses and the concrete
will safely carry all the compression
stresses.
-The reason why concrete Is an eco
nomical building material aside from the
fact that IL fireproofs the steel reenforce-
ment Is, as one engineer well expressed
it, One dolla, will buy as much COM
pressive strength in concrete as two
dollars will in steel
! SThus this combination utilizing the
economical concrete to support the COM
nressive loads and the equally economical
steel rods to Withstand the tensile strains
produces the cheapest and most service
able building material so far discovered,
reinforced concrete.
.The reason that the building OF houses
| in REINFORCED concrete has Jagged behind
it's application to other lines Of building
lies in the feet that practically all Of the
concerns that have entered the reinforced
concrete construction business have de-
voted themselves to the construction Of
factories. warehouses. &o.. because the
large MASSES Of material contained in
this type Of building and the simplicity
OF its other details made the formation
Of an organization capable OF such oon-
struotion much simpler matter than
one equipped for house construction.
aIn a concrete factory. for example,
practically rs per cent. Of the entire cost
of the work is in the making and placing
of the reinforced concrete. In the build
ing of a house. on the other hand. the
cost of the concrete az compared TO the
total cost Of the house with it's plumbing
and heating and lighting and interior
decoration rarely exceeds 25 per cent.
Of the total.
aThe concrete engineering firms In the
Industrial field have steadfastly refused
contracts for house building on account
Of the appalling amount Of smsll detail
In such work. Take. for example. the
construction of such building as the
Bush terminal warehouse In Brooklyn.
One Of the largest single items in this
building aside from the concrete con-
sists Of window frames and sashes.
"The engineer designing them studied
the conditions and drew the plan of a
A. FV,t-