The Hawaiian star. [volume] (Honolulu [Oahu]) 1893-1912, 1912-01-22

I
| WASHINGTON, December 22.-The
use of oil in the construction of roads
lis receiving much attention at the
hands of the public roads bureau of
the Department of Agriculture. The
statement is made by Director L. w
Page of the bureau that the use of oil
mixed concrete has been found very
successful, and one of the most prac-
tical of the recent discoveries in bring
ing about resilient, dustless. non
absorbent road material capable Of
withstanding the severe attacks Of
automobile traffic.
The good roads officials say that the
practical tests Of oil-mixed concrete
roads are now in progress in Washing
ton, on Staten Island, and on several
bridge floors in Ridgewood. - J They
say that laboratory tests show that in
general oil has the following effects
on mortars or concrete mixtures: Ten
sile strength, not decreased time of
setting is heightened; crushing
strength. somewhat decreased; tough
ness, not decreased; elasticity, not diff
ferent from ordinary concrete alb
sorption and porosity, greatly de-
creased, and bond, slightly decreased
Giving an account of the method for
bringing about the best utilization of
oil in concrete, Director Page in his
report says:
The best method of preparing Oil
mixed concrete is to mix together dry
the required quantities of cement and
sand until of uniform color, then add
water and mix to a mortar of the de-
sired consistency, The required guam
tity of oil is then added to this NOR
tar and mixed until it entirely disap-
pears. The oil mortar thus formed is
then added to the previously moist
ened coarse aggregate, and the mass is
turned until thoroughly mixed. Ten
( per cent OF oil based on the weight Of
( cement in the mixture is all that is
required to produce concrete with
very small water absorption and per
cent of oil is nearly as efficient.
( Roughly speaking, a mixture contain
ing 5 per cent of oil win require five
quarts Cabout one-half bucket for
every two bags of cement In using
a machine, experience has shown that
oil-miXed concrete may be mixed most
eXpeditiously by placing sand and ce.
ment in the mixer and adding enough
water to form a thin mortar. oil Is
then added alternately with the stone
until enough oil has been added to the
batch, when the remainder of the
stone is added and the mixing contin-
)ued until completion. The types Of
oil best suited for oilmiXed concrete
work are fluid residual petroleums.
/ In connection with the use of oil in
certain processes of road making, Di-
rector Page says:
| A public patent, which has aroused
much attention throughout the cOun-
try has been granted for mixing oil
with Portland cement concrete and
| hydraulic cements giving an alkaline
reaction, so that any one may use this
process without the payment of royal
ties.
An account of the chemical tests
and experiences of the government
| through laboratory work, to determine
the best road making material and the
most effective ways of utilizing such
material, is set forth by Director Page
as follows;
During the year 324 samples of vari-
Gus materials were received for exam,
nation in the chemical laboratories
This is nearly twice the number eX-
amined during the fiscal year 1910 and
over four times the number examined
in 1909. OF these thirty-eight were
reduced and residual petroleums, dis
tllates, etc. lightweight oil asphalts
blown oils and cut-back oil asphalts
four matthias, thirty-two native as
DldllS, llltt tllluloll glhb bllo an
emulsions, thirty-siX crude and refine,
water-gas tars, forty-seven crude an'
refined gas-house coaltars, twenty
eight coke-oven tars, two crude an
refined wood tars, three tar and as
J phalt mixtures, six rock asphalts AM
bituminous aggregates, twenty-on
rocks, cements, brick and gravel an
sixteen miscellaneous materials not il
F cluded under the above headings,
The economic utilization of yariou
t coke-oven tars in the preparation q
roads binders has also been given cor
= sideration, and the results of this II
= vestigation will appear shortly in tn
e form Of a government publication
p Among other problems of progre
,, sive nature covering rather long pc
s. RODS of time are studies Of the e
j. fects of light and of weathering o
l. various bituminous materials, and tn
results will be published from time