The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1903-05-07
CITY NEWS.
NOT A SURE THING
Recent Occurrences Cast Doubt on
Value of Concrete for
Grain Tanks.
Under Some Circumstances It's Prac-
tically Indestructible, but Con-
ditions and Materials Differ.

Within a fortnight the attention of
engineers and builders the country over
has been drawn to the northwest by two
occurrences of nature involving the
question Of the use Of concrete as
building material. A portion of the new
concrete building Of the Johnson Electric
service company In Milwaukee fell. carry
ing down the upper part of the front wall
and entailing heavy loss Shortly after
this one of the tanks of the big Peavey
concrete elevator at Duluth gave way
Two years ago a Canadian tank collapsed,
followed by another later on. This was
attributed to the fact that the work mad;
not sufficiently hardened before grain was;
taken in Last week another tank col!
lApsed, and on Monday the fourth one
gave way, the fax contained In 1t rushing
out with great force.
The interest aroused by these recur-i
rences has been widespread and especially
keen here, since Minneapolis Is a great.
center for grain elevator construction IN
which work the increasing use OF con-
crete has of recent years been feature.
While concrete in one form or another
has been used for centuries. many en-
gineers are inclined to the view that, as
a material of which to construct grain
elevators, concrete Is not yet entirely past
the experimental stage. That any num-
Der Of prominent American engineers
should hold this view: that they should
acknowledge that there are possibilities In
the use Of concrete beyond what the
engineer can positively know about at
the outset, is matter OF worldwide I'M
portance, A few years ago when. the
first large concrete tank house was erect
ed, 1t was predicted that the elevator
building industry had been revolutionized
and that concrete would speedily super
sede other material In the erection OF
great terminal storage houses. 1t now
u l.. Se,I ,ryv a
Uncertainty In Material.
William r, Sinks. superintendent OF the
construction department of the Barnes &
Record company. Is inclined to the view
that the use Of concrete IS IN sense
even yet experimental.
"To my mind said Mr.. Sinks to-day,
"the most important factor initiating
against the use of concrete In the con-
struction of grain elevators. lies in the
fact that there Is about 1t a modicum
of uncertainty. One knows the material,
what it has done and what should be ex-
pected of 1t. In using it one calculates
even beyond the scope of the engineer in
an ordinary work. The effect of the
slightest possible settling of the ground,
the lateral pressure on the tanks from
the interior, the proportionate increase Of
lateral pressure in the drawing out Of
the grain, these and numerous other
points may be reduced to calculations so
accurate and so minute as apparently to
eliminate from the work every iota Of
chance or uncertainty. Yet, when one
leaves work of this kind, he cannot
be free from the fear that all is not right,
that somewhere in the chain there Is a
weak link. He carries nervous fear tina t
somewhere it may break, as 1t often
does in places and under circumstances
most unexpected.
1.-THE arguments favoring concrete for
grain elevator construction are brief but
weighty. Such structures cannot decay,
time only hardens them and they require
no insurance. AS a matter of fact, how
ever. concrete is no such fire proof ma ter
ial as is generally supposed. When stone.
cement and water unite, chemically the
water does not leave by evaporation, but
in the adhesive process becomes absorbed
into the whole remaining in different
chemical form. Given sufficient heat and
this assumes the form of gas and passes
Off Five hundred degrees of heat will
cause some preliminary disintegration
Nine hundred degrees will totally destroy
the compound. returning it to a rude, ir-
regular. granular form. l do not look for
much more construction of concrete tank
houses. Personally I am pretty we'll com
m1tted to the use of tile. These tile tank
houses that have gone up in Minneapolis
are as understandable as the ingenuity OF
man can make them. The tile burns fol-
two or three days in heat equal to 2,70t
degrees fahrenheit, in the process of man.
ufacture. About two years ago we made
test here that attracted the attention
of the engineering world We built 2
tank near Pillsbury A mill and furnace
next It, and succeeded in directing 20Ot
degrees of heat against the side for hours
without the slightest effect. This I be
lieve to be the material that will entej
into all the big terminal houses of tn,
future