The Detroit times., 1911-02-23

ana moulded simultaneously with
os Ser e sRofS TOR cSss, OF ~ y.
walls. beams. girders and floor con-
struction. shall be mixed I'm proper
land cement to two CD parts or sand
and not more than four CD parts OF
either broken stone or gravel
The concrete for columns, shall be
mixed I'm the proportion OF one CD
part Portland cement. one and one
half Uh) parts OF sand and three
Ss) parts OF broken stone or gravel
In no case shall more than two t1)
parts OF sand be used to one 81 part
All mixing shall be done by machine
III the total amount OF concrete ex-
ceeds nifty ib0)- cubic yards. ~
The proportions OF the ingredients
urement Clean water free from
strong acids or alkalis must be used
In all mixing.
Iron Stag or other similar porous
broken stone or gravel. when 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 20 have the voids
ton by volume. OF one I'D part Port
properly filed
sse. IL; oguAIL5ITr OF Mater
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 steel
conform 10 the following limits In
chemical composition
PHOSPHORUS shall not exceed 10
per cent.
Manganese shall not exceed so per
Carbon shall not exceed go per cent.
All steel shall conform 10 the fol-
lowing physical requirements;
shall not be less than sixty thous-
and (60.00o) pounds per square
inch OF net cross section.
The yield point shall not be
less than one-half tlA) the uiti-
The eionsation per cent. in eight
(S) inches shall not be less than
00-ultimate strength. with
modification as follows: For each
thickness. above three-quarter tk)
inches, a deduction OF one Cd per
cent; for each decrease OF one-six-
teenth u-1s) inch In thickness, be-
deduction of two and one-half
(2h) per cent.
Test specimens for bending shall
be bent cold around q diameter
equal to their least thickness. to
tho following angles without frac-
tpre on the outside OF the bent por-
ton:
For specimens one Cd inch thick.
80 degrees.
For specimens ree-quarter (E)
inch thick. 80 degrees
For specimens one-half ND inch
thick. lilo degrees.
For specimens one-quarter (h)
inch thick. $50 degrees.
ts-16) inch thick. lao degrees.
For specimens one-eighth (h)
inch thick l60 degrees
tb) CEMENT. The Portland
dard specifications OF the American
Society for Testing Materials. In
force Dec. 1, 1910. except that the
minimum requirements Tor tensile
strength shall be as noted In Sec
(c) SAND. The sand shall be
clean. free from any organic mat
ter and graded from coarse to hne.
(d) STONE. GRAVEL OR STAG;
stone, free from dirt or dust and
freshly broken.
The gravel shall be washed
The Stag shall be clean crushed
All aggregate must be or such
size as will pass through a three
quarter (A) Inch screen and be re-
tanned on one-quarter tA) Inch
Sec. 1s. MATERIALS PRoHIB-
TIED. The following materials
shall not be used In reinforced con-
crete construction: Boiler cinders,
Pn aS. ali Similar III injurious Sn's msteriais
Sec. 16 CENTERINC AND
FORMS. All monolithic reinforced
concrete shall be built on centers
All forms shall be built strong.
unyielding, plumb and true, thor
oughly braced and with tight
joints. so that no appreciabie part
OF the concrete mixture can escape,
carry ali of the usual loads which
may cone upon them without
spring or detection.
For columns an opening shall be
left at the bottom OF the form. Tor
The opening shall not be closed
until the column Is to be poured.
Columns over fourteen 1D feet
in height. and under eighteen l1s)
inches square, shall have an inter-
mediate opening or pocket and the
pouring started therefrom. The
forms shall be thoroughly cleaned
immediately before the concrete IL
pOure0, anu Ill chips, ice anu OthcE
foreign matters removed.
Before removing the shores un-
der any beam or girder, the column
supporting IL shall be stripped, SO
that the column may be examined
on all sides.
III 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
h. within vi two (I2
hours after pouring.
The sides OF girder and beam
forms, may be removed at the ex-
piration Of six (6) days after pour
fhe time which must elapse be-
fore removing the shores under the
girders ard beams, will vary with
the design and the conditions OF
the weather, but in no case shall
thoy be removed in less than three
(2) weeks after pouring.
The supports under Moor slabs
shall not be removed In less time
than ten tlo) days after pouring.
but this clause is not intended TO
prevent removing the toists and
tagging within a less time, provid-
ed the slabs are kept properly
shored up.
FoRCEMENTS. All reinf9rcins
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-half uhl
inches thick on the bottom and
side OF girders and beams and
three-auarters (%) inch on bottom
The amount of concrete protec=
ton shall be clear of the reinforc-
ing members.
Exposed metal centering or ex-
posed metal OF any kind, shall not
be considered a factor In the
strength Of any part OF any con-
Sec. is PLACING OF con-
CRETE All concrete is TO be what
a. L,o,.x, evvat raiwfnra'