Ladysmith news-budget. [volume] (Ladysmith, Rusk County, Wis.) 1907-1927, 1915-09-10

between the two portions will be
soundly and firmly made.
While the cofferdams are being
made a stone crushing plant is being
erected to make ready the materials
for the concrete work. That is, pro.
vlded the conditions are such that the
material to be used is crushed stone.
Sometimes suitable gravel is found in
| the neighborhood of the work, in
which event a temporary Industrial
railway is constructed from the source
of the gravel supply to the site of the
work. In either case the gravel or the
crushed stone are stored in bins from
which they can be readily supplied to
the concrete mixers which are to make
the concrete for the structure.
Concrete Reinforced With Steel.
All the concrete work which enters
into the building of dam on the Chip.
pewa is reinforced with steel. This
material comes on the job in the shape
of straight or twisted round and
square bars, and 1t is bent into the
forms required on the spot. The
amount of steel which will enter into
the construction of the next dam to
be built on the Chippewa is estimated
by the engineers to be eighteen car
loads. The popularity of the use Of
steel reinforcement in concrete work
is that steel and concrete expand and
contract evenly with changes of tenn.
perature Were the reverse the case
the one material would part from the
other with increased heat and cold
conditions, and the result would be
that the structure would be rent asun-
der.
| AS soon as the Golfer dams are
cleared out of the debris everything
| the foundations forms for the struc-
ture are set up. These are made Of
the product of the saw mill which has
already been described. AS matter
of fact few dams are made Of solid
concrete. Usually the space between
the upright wall which holds back the
water and the concrete apron or slope
over which it runs gently to the lower
level of the river downstream, is hol-
low. In some dams the apron is slab
of concrete not more than eight inches
thick supported on pillars underneath
| formed by the walls between the hOl-
| low spaces. The side walls OF the
dams, or wing dams as they are called,
which run from the main structure
| holding back the rivers main body
well into the banks, are also of con-
crete reinforced by puddle earth. That
| Is, core-wall of concrete is built
! to give the finished earth wall great
power to resist pressure, and then the
cays and earths are puddled up on
either side of it to give it bulk and
additional strength.
I AS the work progresses immense
quantities of material are used. In
such a dam as may be built upon any
of the sites now under examination
on the Chippewa 100000 barrels Of
cement will be used. The total weight
of this material alone will be about
| BIZ 800 900 pounds, cement weighing
approximately 375 pounds to the bar
rel Ordinarily a single barrel of CO.
ment will be required to make cubic
yard of concrete, the proportions being
usually one to five, so that the const1-
tuents of the concrete which go into
It with the cement will represent
weight of five times that of the ce-
ment, or an additional 1S7,50O,000
pounds. With the steel and all added,
| fri Of that
be put at whichever of the locations
On the Chippewa Is selected this month
| for the next dam will represent total
weight of 25O,000,000 pounds. This inn
mense weight is the barrier which,
has to be opposed to the imprisoned
waters of the river, held back at a
height of 40 or so feet above their
usual elevation when flowing natural
" down stream.
The Pond Cleared of Trees.
AS the builders have been at work
IN the dam other laborers are busy at
nverfOWed when the dam gates are
closed. Every tree and stump and
avery bit of fallen timber that lies
npon the area to be Overf1owed Is cut
off or taken away. The reason for
this is that the trees would die any
way and the stumps and logs would be
uplifted by the force of the water and
The frosts and all of them floating over
The dam would constitute a menace to
It's safety When the dam Is up and
before the cofferdams are removed a
special water-proof1ng treatment Is
giyen the concrete that is below water,
Inst as later on similar treatment is
riven that above water. Incidentally
It may be of interest to readers Of this
oaper who are DESTROYS Of water proof
ng concrete structures of their own
% know that a water proofing mixture
used in this work is readily made and
Is quite adaptable to domestic con-
crete work Three parts of kerosene
and one part of coal tar are mixed
70 the consistency of paint and APP
oiled to the concrete. 1t constitutes
The simplest and quite the most eff
fective waterproofing of concrete that
can be devised outside expensive