The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1911-02-20

steel brackets OF by concrete brack-
cts: properly reinforced. and con-
and moulded simultaneously with
Sec. Is. PROPORTIONS OF IN
GRADIENTS. The concrete for
walls. beams. girders and floor con-
land cement TO two CD parts OF sand
and not more than four CD parts OF
either broken stone or gravel.
The concrete for columns. shall be
mixed In the proportion OF one Cd
part Portland cement. one and one
ca parts OF broken stone or gravel
In no case shall more than two CD
parts OF sand be used to one I'D part
:. All mixing shall be done by machine
N the total amount OF concrete ex-
ceeds nifty (50) cubic yards
The proportions OF the ingredients
must be ascertained by actual meas
uremsnt. Clean water FREQ from
strong acids or aikalis must be used
In all mixing.
Iron Stag or other similar porous
materials. may be used In place Of
broken stone or gravel, whom ap-
proved by the Department Of Build
ings, and In such cases the Depart
ment of Buildings may require a
reduction In the proportion of the
Stag or other similar porous ma
terial In order to have tho voids
ton oy volume. OF one Cd part Port
I. See u a S4hET OF q, n MATGR.
ing bars used In reinforced con
crete. shall be made by the open
hearth or the Bessemer process,
bars TO be rolled directly from the
original billet. No rerolled steol
will be allowed. The steel shall
conform to the following limits In
chemical composition
PHOSPHORUS shall not exceed 10
per cent.
Sulphur shall not exceed .oe per cent.
Manganese shall not exceed so per
cent.
Carbon shall not exceed so per cent.
All steel shall conform to the fol-
lowing physical requirements:
The ultimate tensile strength
shall not be less than sixty thous-
inch OF net cross section.
The yield point shall not be
less than one-half (h) the uiti-
mate strength.
The elons alton per cent. In eight
go inches shall not be less than
1.40o. 900 ultimate strength. with
modification as follows: For each
increase OF one-eighth (h) inch I'm
thickness, above three-quarter (k)
inches, a deduction OF one Cd per
cent; for each decrease of one-six-
teenth u-l6) inch In thickness, be-
deduction OF two and one-half
Test specimens for bending shall
be bent cold around a diameter
equal to their least thickness. TO
the following angles without frae-
ture On fha out aide Of the bent nor
ton:
For specimens one Cd inch thick.
For specimens three-a quarter (x)
inch thick. 30 degrees.
For specimens one-half (h) inch
For specimens one-Quarter (h)
inch thick. $50 degrees.
For specimens three-sixtesnths
(s-lO inch thick. 40 degrees
For specimens one-eighth (hD
1 obS ' cEME M 'es, The Portland
cement shall conform to the stan
dard specifications OF the American
Society for Testing Materials, In
force Dec. l. 1910, except that tn. the
strength shall be as noted In sec
tion rs Of this article.
(c) SAND. The sand shall be
clean, free from any organic mat
ter and graded from coarse to fine.
(d) STONE. GRAVEL OR STAG:
The stone shall be clean crushed
stone, free from dirt or dust and
The gravel shall be washed
clean. :.
The Stag shall be clean crushed
blast furnace Stag.
size as will pass through q three
quarter (%) Inch screen and be re-
tanned on q one-auarter lAD fnch
screen. sa.r.eAs- ~
Sec. Is MATERIALS PRoHIB-
TIED. 1.-THE following materials
crete constructions Boiler cinders.
plaster OF paris. suiphate or lime
and all similar Injurious materials
Sec, IS CENTERING AND
FORMS. All monolithic reinforced
concrete shall be built on centers
All FORMS shall be built strong.
unyfelding, plumb and true. thor
oughly braced and with tight
joints, SO that no appreciable part
OF the concrete mixture can escape,
and they shall be supported to
carry all OF the usual loads which
may come upon them without
spring or DETECTION.
For columns an opening shall be
left at the bottom of the form, for
The opening shall not be closed
until the column 10 to be poured.
Columns over fourteen CAD feet
in height, and under eighteen (1b)
inches square, shall have an inter
pouring started therefrom. The
forms shall be thoroughly cleaned
Immediately before the concrete IL
poured. and all chips. Ice and other
foreign matters removed.
nAE m hA a
der any beam or girder. the column
supporting II shall be stripped, SO
that the column may be examined
on all sides.
II ample shores are used to carry
the full weight OF the floor. column
forms may be removed as soon as
the concrete has set up hard. pro-
vided that the said forms shall not
be removed within seventy-two CID
hours after pouring.
forms, may be removed at the ex-
piration Of six te) days after pour
The time which must elapse be-
fore removing the shores under the
girders and beams, will vary with
the design and the conditions Of
the weather. but In no case shall
they be removed I'm less than three
CD weeks after pouring.
The supports under hoor slabs
shall not be removed In less time
than ten t10) days after pouring.
but this clause IL not intended to
prevent removing the toists and
tagging within a less time, provid-
ed the slabs are kept properly
Sec IL PLACING OF REIN
FORCEMENTS. All reinforcing
members shall be accurately locat-
ed In the forms and secured firmly
against displacement. They shall
have a protection OF concrete. not
less than two CD inches thick for
columns. one and one-haif q u
inches thick on the bottom and
three quarters ca inch on bottom
OF floor slabs.
The amount OF concrete protec-
tion shall be clear OF the reinforce
ing members.