Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1916-01-27
Says Il is Best Material Avail
able for Permanent Road
Work; Will Report

Whether the STA er2isoTs shall favor
the laying OF bitulithic or warren,
| tie coat on top of concrete, base or
on top of q crushed rock base formed
the basis OF a discussion late in the
meeting of the supervisors last night,
with the final decision to refer the
Kalakaua avenue specifications to the
engineer with instructions to prepare
a report On six-inch concrete founda-
ton with a bitalithic top of two
inches. s..>-. -. -.
Engineer Collins stated in a report
to the board that a thickness of three
fourths of an inch is not to be recon-
mended, owing to the fact that prac-
tically as good a construction can be
obtained by the application of dou
BILE squeeze coat of asphalt and
crushed rock screenings. 49,.
He stated that various cities of the
mainland have specified layer OF
from one to two inches of bitulithic
material on five OF six inch layer OF
concrete, a binding coat being used
between the two layers.
A second report was fled with the
board by the engineer following
thorough examination carried on dur.
ing the last few days by his depart
ment to ascertain the character of the
soil on Kalakaua avenue, His report
ron the investigation is as follows:
Collins Formal Report.
Honolulu, T. H., January 26, 1916.
ITO the Honorable Mayor and Board
of Supervisors of the City and
County of Honolulu.
Gentlemen:
I'm compliance with the direction
of your board, the undersigned City
and County Engineer has made test
borings on Kalakaua avenue, and sub
mits sketches of the same herewith
as Exhibit l.
After careful study of these Dor
ings the following conclusions have
been drawn with respect to the pro-
posed paving:
Il. For the first $500 feet of the
length to be paved there will still re-.
main as a subgrade approximately six
Co inches of coral, under which is a
layer of black loan and sand. That
the ground water level for the same
distance is within eighteen 18)
inches of the subgrade. ..-..-.......
"2. That for at least 5000 feet of the
distance to be paved, the subgrade
will be composed of black loan and
sand, the present existing coral sur
face having been entirely removed as
shown by test holes 8 and 4. Further,
that the ground water level for the
same distance is from two ~ to three
and one-half g 1-2) feet below the
subgrade. vi.
"3. That owing to the comparatively
fiat grade of Kalakaua avenue and the
added cost of the improvement, any
scheme of sub-drainage would be i'm
practicable.
a That the sub-grade for the pro-
posed pavement can not be improved
except by excavating and refiIling with
suitable material. which is an expen-
sive operation I'll.
Failure of Crushed Rock.
5. That the asphalt macadam sec
ton already constructed on Kalakaua
avenue furnishes an excellent example
OF the failure of a crushed rock base
to give good service upon poor sub
grade.
1T is the opinion OF this office that
concrete should be used as a founda-
ton for the pavement 10 be laid under
the Kalakaua Avenue Frontage I'M
provement, for the reason that it is
monolithic in character and will
bridge the weak places which are
bound to develop in the subgrade, due
to the presence of ground water. A
crushed rock base will settle under