The Detroit times., 1911-02-23

steel brackets or By ,tonerste .brack-
cts, properly reinforced. and cone
and moulded sim1itsnsonsiy viii
sec. IL, PROPORTIONS OF M
GREDIENTS. The concrete ifoF,
walls. beams, gfrders and moor CON
struction. shall be mixed IN proper
land cement-to. two CD parts OF sand.
and not more than four 90 parts Of
either broken stone or gravel
The concrete for columns. shall be
mixed ian the proportion OF. .oneI I'D
part Portland cement, one and one
half (lixl parts Of rand and three
90 parts OF broken atone or gravel
In no case shali more than two ,(2)
parts OF sand be used TO one ~ part
OF cement 49, ~ teai eits ~
All mixing shall be done by machine
IN the total amount OF concrete ex-
ceeds fifty f60b cubic yards. - "a
The proportions OF the .ingredients
must be ascertained by actual meas
urement. Clean water free from
strong acids 90 aikalis must be used
In all mixing.
Iron Stag or other similar porous
materials, may be used In place OF
broken, stone or gravel, when APP
proved by the Department OF Build
inEs. and I'm such cases the Depart
ment OF Buildings may require a
reduction IN the PREPARATION OF the
terial IN order Co have the svoids
ton. ey volume, OF one CD part Port
Sec i4'r ouALirY OF MATER
inr bar. s Used sf m rein no cstpt esn-
crete. shall be made by the open
hearth or tho Bessemer process,
bars TO be rolled directly from the
original billet. No .rerolled steel
win be allowed: The steel shall
Chemical eomposition
Phosphorous shall rot.-exceed 10
per cent 1Af.
sulphur shall not exceed .os per cent
Maganese shall not exceed so per
carbon shall not exceed so per cent.
All STEEL shall CONFORM 10 the fol-
lowing physical requirements:
The ultimate tensile strength
and ieO. ooe) pounds per square
inch of net cross section. ~.
The yield point shall not be
less" than one.haif thp the uiti<.
mate strength. -.
yes nsss. s:ss PC: ss S 81 il. I. s ssa
l.4oo, 900 ultimats strength. With
modification as follows; For each
increase OF one-efghth CD inch In
thickness. above three-quarter ~
n
cent; for each decrease OF one six
teenth u-1s) inch IN thickness, be-
low Ave- sixteenths t6-16) inch. Q
dsabpction q two and one-haif
fest specimens for bending shall.
be. bent cold around = diameter.
equal to their least thickness, 10
tho following angles without frac-
ture on the outside Of the bent por-
For specimens one I'D inch-thiok.
For specimens e-quarter tk)
inch thick. 30 degrees
For specimens one-half Ga inch
thick. 10 degrees, -..... -,,,,
inch thick. iso degrees.
{s-fsJ Inch thick. 40 degrees:
For specimens one-efghth th)
t eSS t eEME asG. d'sE Tss Portland
cement shall conform 70 tne stan
dard specifications OF the American
Society for Testing. Materials, IN
force Dec. I. 1910. except that the
strength shall be as noted In, sec
ton 25 OF this article.
(c) SAND. The sand shall be
clean. free from any organtc, mat-a
ter and graded from coarse to me,
The stone shall be clean crushed
stone, free from dirt or dust And
The gravel shall be washed
The Stag shall be clean crushed
blast furnace Stag.
All aggregate must be or such
size as will pass through q three
quarter (&) Inch screen and be re-
tained on one-quarter GA inch
Sec is. MATERIALS PRoHIs-
TIED The followine materials
shall moi. be used In, reinforced corl,s
creta construction: Boiler ctnders.
plast e. ~ sspns'1 ~ ms
sec Is cENTERiNG AND
FORMS. All monolithic reinforced
concrete, shall be built on centers
All forms shall be built strong,
unyieiding, plumb and true. thor
oughly braced and with tight
joints. so that no appreciebie part
OF the concrete mixture can escape,
and they shall be SUPPORTED 90
carry all Of the usual loads which
may come upon them without
spring or detection. 90. a. ~
For columns an opening. shall be
left at the bottom of the FORM, Tor
cleaning and adjusting the steel
until the column In to be poured.
Columns over fourteen rl(14) feet
in height. and under eighteen (10
inches square, shall have an inter
mediate opening or p possEe, and rhs
forms shall be thoroughly cleaned
Immediately before the concrete In
poured, and all chips. ice and other
foreign matters removed.
Before removing the an, shores cn,,, um,3
supporting II shall be stripped, so
that the column may be examined
on all sides. 49, ast .
II ample shores. are used to carry
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-twot 72} ,
hours after pouring.
The sides OF gfrder and beam
forms. may be removed at the ex--
piratisn Of SIX ts) days after pour
The time which must eispse be-
fore removing the shores under the
girders and beams. will vary with
the design and the conditions of
the weather. but I'm no case shall &
they be removed I'm less than three
OBJ weeks after pouring. -.
The supports under hoor slabs
than ten t10) days after pouring.
but this clause In not intended to
prevent removing the totsts and
tagging within less time, provio-
ed the slabs are kept properly
sbored %. ~
Sec. ia PLACING OF REIN
FoRCEMENTs. All reinforcing
members shall be accurately leeat-
ed In the forms and secured firmly
against displacement. They shall
have a protection OF concrete, not
Columns. one and one -half t1hl
inches thick on the bottom and
side OF girders and beams and
three-quarters CID inch on bottom
0tThe amount or concrete protec-
tion shall be clear, of the reinforc-
Exposed metal centering or ex-
posed metal OF any kind. shall not
be considered a factor in the