The Daily Ardmoreite. [volume] (Ardmore, Okla.) 1893-current, 1915-06-11
MIXED CON
CRETEF0R DAMP
PROQF|NC c
EXPERIMENTS IN DEPARTMENT
OF AGRICULTURE DEMON
STRATE ITS VALUE IN MANY
KINDS OF BUILDINGS.

| SECURED results W ulCu appear 10 tSldO
lish definitely the value of oil mixed
concrete for damp proof construction
Detailed results OF these tests, which
We're carried out in connection with
the work of the office of public roads
are contained in the new bulletin.
No. 23O, of the department, entitled
"Oil-MiXed Portland Cement Con
crete" Briefly summarized, the con
clusions to be drawn from them are
that the admiXture of certain min
eral oils in small proportions, not to
exceed 10 per cent of cement used,
does not lessen the tensile strength
of mortar; that the decrease in the
cOmpressve strength of mortar and
concrete is not serious; that concrete
mixed with oil takes much longer to
set hard, perhaps twice as long, but
that the increase in strength is near
ly as rapid in the oil-mXed material
as in the plain concrete. The use
of oil does not make the concrete
impervious to heavy water pressure
but it does make it practically non
absorbent under low heads.
The value of oil-miXed concrete is
said to be particularly great in the
construction of basement floors and
walls, watering troughs, cisterns,
barns, silos and in all parts of con
crete structures that are to be made
damp proof.
The oil should in no case exceed 10
per cent of the weight of the ce-
ment and for the most part per
cent is all that is necessary. Since
bag of cement weighs 81 pounds,
A. pounds of oil, or about , -
quarts, should be added for each bag
of cement used in the mixture. The
sand and cement should be first mixed
with the proper amount of water into
a stiff mortar, to which is added the
correct amount of oil, and the whole
mass again thoroughly mixed until all
traces OF oil have disappeared. Par
ticuar care should be taken to in
sure that the oil is thoroughly ncor-
porated in the mixture and the time
of mixing should be practically double
that when the oil is not used. For
this reason continuous mixer
should not be used in oil-cement-con-
crete work, as it is difficult with this
type of machine to increase the time
of mixing sufficiently.
The kind of oil is also important
and the following technical specifi
cations are suggested in the bulletin
n order to prevent the use of certain
oils which might tend to impair the
strength of the mortar or the con
crete
q) The, oil shall be a fluid petrol
cum product and shall contain no ad-
mixture of fatty or vegetable oils.
(2) 1t shall have a specific gravity
not greater than O945 at a tempera.
ture of % degrees c.
(3) 1t shall show a flash point of
not less than $50 degrees c by the
closed-cup method.
(4) When 24O &C. of the oil is heat
ed in an Engler viscosimeter to sol
degrees c. and maintained at that
temperature for at least three min
utes, the first 100 &C. which flows
out shall show a specific viscosity Of
not less than Is nor more than 80
C5) When part of the oil is shak-
en- up with parts of the hundredth
normal caustic soda, there shall be
no emulsification, and upon allowing
the mixture to remain quiet, the two
components shall rapidly separate in
distinct layers.
For practical use the addition Of
oil will be found particularly useful
in the construction of basement floors
and walls. Many of these now in eX-
istence are continually damp and such
a condition may be remedied by the
application of an oil mixed mortar
coat to the old surface. A mortar
of one part of cement and
two parts sand and containing per
cent OF oil should be sufficient non
absorbent for this purpose.
Watering trOughs and cisterns |
made of oil-mixed concrete should
also prove of considerable practical
value in the conservation of water.
In the construction of barns, where
oil-mixed concrete is used. the inter
ior will be noticeably drier than when
ordinary concrete is used. Owing to |
their durability. cleanliness. and re-
sistance to fire. concrete barns are
becoming more and more popular. |
but they suffer from the disadvan-
tage that during a long beating rain |
the side walls are inclined to absorb |
mUCh moisture Uhich t,Itip,afaTtr I