The Detroit times., 1910-12-07


such hneness that not more than
ten uD per cent will he rejected
ny sieve OF twenty-five thousand
tss, 0oO meshes per square inch.
and In addition IL shall be capable
OF sustaining without rupture
tensile stress or at least six hun
drad 5000 pounds per. square inch
after one ID day In air and TWEEN
ty-seven CAD days I'm water. and
all cement shall he subjected TO
tests az may be required I'm this
Ordinance.
Sec. >. MoRTARs. tA) Lime
mortar shall be made from one tD
part fresh lime and not more than
four ~ parts OF sand.
,B) Cement mortar shall be
made from one Cd part cement
and not more than three ,D parts
(CJ Cement and lime mortar
shall be made with equal parts OF
cement and lime. and not more
than three CD parts OF sand TO
each whole part OF cement and
lime.
Soc. 10. PROPORTIONS or
CONCRETE. The proportions OF
materials for concrete used I'm
foottngs. foundations. walls and re-
tanning walls shall be as follows:
Not less than one part OF cement
90 parts OF either broken stone.
Stag or gravel. to be thoroughly
mixed with the proper proportions
or clean water.
In quantities of over nifty 900
cuoic yards, the concrete Is TO be
machine mixed
All concrete shall be Used imme-
diately after mixing. and the ma
tertals shall be mixed by measure.
Sec: IL. PORTLAND CEMENT
BRICKS. Portland cement bricks
made of Portland cement OF the
same dimensions as common brick.
may be substituted. except FOR
walls. piers and buttresses sustain
ing heavy weights. provided said
form to the tests for materials pre-
Sec. IL. ARTIFICIAL STONE.
Artificial stone, made OF Portland
cement and incombustible and
waterproof material. may be used
as substitute. for any natural
stone. But no drtinciai stone con-
tanning more than fifteen u5) per
cent or lime or crushed limestone.
shall be used as Intel or bearing
stories high.
Artificial stone must conform to
the rests for materials prescribed
In this Ordinance.
Sec. Is. WROUGHT IRON. All
wrought iron shall be ibrous.
tough and ductile. uniform in char
acter and having an ultimate ten
sile strength OF not less than
forty.cight thousand (4s.000)
pounds per square inch with a
Yield point or commercial elastic
unit OF twenty-six thousand Geo.
Vool pounds and an elongation of
elshteen tls) per cent In eight tsl
Inches. including fracture when
tested In small specimens.
Sec. "a. CAST IRON. Except
where chilled iron is specified. all
castings shall he tough grey iron,
iree from injurious cold shuts or
olow holes, true to pattern and
hsVlns an ultimate tensile strength
or not less than sixteen thousand
us,oO") pounds per square inch.
sample pieces one CD inch
square, cast from the same heat OF
metal In sand moulds. shall he
capable or sustaining on clear
span or four ca feet and eight 1S)
inches. center load OF five hun
ured tto0b pounds when tested In
the rough bar.
Sec. Is. STEEL CASTINGS. Steel
castings shall be made by the open
hearth or crucible process and shall
be free from injuries. and blow
holes and shall have the following
minimum requirements:
All steel castings shall be an
nealed.
sample bars to develop at least
thousand 100000 pounds per
square inch. with a yield point or
commercial elastic limit OF thirty
one thousand five hundred (3l, 500
pounds per square inch and an
elongation OF eighteen Gs) per
cent In two CD inches. including
fracture and a reduction OF twenty
five t25) per cent In area.
Sec. l6. STRUCTURAL STEEL
All structural steel including rivets,
shal have their physical and chem
zeal properties in accordance with
the Manufacturers Standard Steel
specifications, as revised to Febru-
airy .. 1903. and as found In the
hand books OF steel manufacturers.
Sec. Il. TESTS. The Depart
ment OF Buildings may require. at
any time. certified copies OF full
inspection from recognized experts.
Tor any or all materials used in
buildings OF Types and and no
such materials shall be concealed
or built upon. until the Depart
ment or buildings. upon their re
quest. shall have been furnished
with satisfactory proof that such
materials and workmanship are
fully equal to the standard.
Sec. is. NEW MATERIALS. Be-
fore any new materials not here
tofore employed are used as con-
structional parts OF buildings or
structures. permission must be OBJ
tanned from the Department or
Buildings. who shall apply such
tests to the said new materials as
may be necessary to determine the
strength and durability OF such
materials.
ARTICLE Y.
Calculation ar Stresses.
section 1. CALCULATION Oh
CONSTRUCTION. Tie stresses OF
materials hereafter used in the
construction OF buildings or struc-
lures. shall he the calculated
stresses due 10 the. dead load
plus the live load
The allowable factors or units OF
safety. or the dimensions OF eacn
piece or combination OF materials.
required in a building or structure,
shall be ascertained by computa-
tion according to this ordinance.
Sec. .. TEST OF FRAMES.
When test OF any framed struc-
ture is required to ascertain its
physical strength or its resistance
10 fire, frost or water, such tcst
sizes, and a similar exposure as
their proposed use In the building
requires. and when the condition
for such tests are not established
in thus Ordinance. the method OF
the authorities prescribed In the
previous sections shall be followed.
Sec. 3. FACTORS OF SA FE.Ti.
In computing the working stresses
in the framing of any building un-
less the safe loads are prescribed in
this Ordinance. the following mini
mum factors of safety shall be used:
r'or cast iron or steel subject to
compression or tension or trans
verse strains. g.
For cast iron subject to tension
or transverse strains, 10.
For cast iron subject to compress
sion for plates and columns OF or
binary or short length according
to the uniformity OF the thickness
OF she'll. q to :.
For cast iron columns according
to the uniformity OF the thickness
OF shell. 5 to 10.
For timber subject to tension
and transverse strain. s.
For timber compressions in short