The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1913-10-22


shalt not be less than that given
y In Article XVI. Section z. IL
10 (b) The working stress shall
II not be greater than that given In
IL Section ), OF this Article.
- tc) Hard tile may be used In
II buildings not to exceed four 90
- stories in height, Ordinary tile
Is may b- used In buildings not tn
Il exceed two stories in height. SOFT
Is tile may be used only I'm Interior |
~ nom bearing walls according 10
20 the requirements OF Article 10
20 'SS [dp All III tile shall be laid in
20 mortar not inferior TO that specii-
"a fled in section s, OF this Article |
Is and shall be carefully bedted IN |
@ SEe S Sin;s b %ns ~e a, 0S eVsrS
IS course. When vertical web con
~ structlon is used in buildings
30 more than two stories high, some
81 special provision satisfactory 10
80 the Department OF Buildings shall
80 be made To insure thorough bed
"a ding OF vertical webs.
35 (D Tile walls faced with brick
Sc shall have header course, every
IS thirty t30) inches, otherwise the
20 brick facing shall not be regard
40 ed IA part OF the wall except that
Al in buildings two stories or less in
~ height metal wall ties every
- eighteen Os) inches In each
~ direction may be substituted for
- header courses.
+6 tD In calculating stress only,
Al those vertical webs In vertical
IS alignment with vertical webs be-
- low may be considered as carry
ARTICLE XIII.
Sec. :. Permits and drawings.
Complete drawings. specifications
3 and details OF all reinforced con-
5 size and position of all reinforcing
s members. shall be fled with the
I Department OF Buildings before a
permit 10 construct such work
10 strain sheets must be submitted
il with the drawings, and specitica-
IL tons.
IL The live loads in pounds per
II square foot for which the differ
10 ent members are designed, shall
16 be marked on each and every
II floor plan OF the drawings sub
Is mitted These dra nsnns, shall Dc b;
20 Buildings as permanent record
81 and shall not be returned as pro-
20 vided In Article III, Section 4.
Sec. 3. Method OF Calculation.
2 In calculating the strength of re-
inforced and plain concrete, used
for walls. columns. beams, floor
s construction or for fireproofing.
s the thickness OF the concrete only
I shall be used exclusive OF any
plastering or floor ballast.
8 Reinforced concrete slabs.
10 beams and girders shall be de-
IL signed In accordance with the fol-
10 (a) The accepted theory OF
- fexure shall be applied to all
Is mep b1 rbs resisting a,sa s Ssnd'n lake all
II the tension stresses.
Is (c) The ratio OF the modulus
Is of elasticity OF concrete to that
20 OF steel shall be ] to Is for a one
II to two to four mixture and TO IL
20 for a one to one and one-half to
% three mixture.
"a (d) The modulus OF elasticity
% shall remain constant at all work
26 ing stresses.
81 le) The stress strain curve OF
% concrete In compression shall be
20 considered as a straight line.
Sec. 4. Allowable unit stresses.
2 The following working stresses.
based on figuring full line and
ta) The allowable unit stress
for plain steel bars shall not be
more than forty-five (45) per cent
OF the commercial elastic limit
and In no case greater than six
10 teen thousand $4,000 pounds per
IL square inch.
Il (b). Deformed high, carbon
l3 steel bars rolled from billets shall
IL not be more than forty-five t46)
Is per cent of the commercial elias
16 tic limit and in no case greater
II than $4,000 pounds per square
IS inch.
10 Co All other steel reinforcing
Il provide compound. tensile and
90 shear members. shall not be more
20 than forty-five (45) per cent OF
q the commercial elastic limit. and
inoa na case sssser POUNDS psy
81 square inch.
IS (d) The allowable unit stress
70 In extreme hbre OF concrete In
20 compression, shall be six hundred
81 and fifty (650) pounds per square
% inch.
80 (e) The allowable unit stress
"a upon concrete In direct compress
50 sion. shall be four hundred and
So nifty (45o) pounds per square inch
81 90 The allowable unit shear
So ing stress upon concrete not re-
40 shall be forty t4o). pounds per
II square inch. The allowable unit
~ shearing stress upon concrete
!3 subject to punching shear or
as enforcement is provided sufficient
as to resist two-thirds ,2-3) of the
~ external vertical shear, shall be
IS one hundred and thirty u3O
81 shears shall be as given in Sec
50 ton H. of this Article.
SO tg) The allowable unit bond
"a ing stress between steel and con-
IS crete shall be taken as eighty
56 (SO) pounds per square inch for
81 plain bars and one hundred t10O)
50 pounds per- per square inch for de-
2 columns reinforced with longi-
3 tudinal bars tied at intervals not
5 the least diameter OF the bars,
s the safe load shall be computed
8 safe load lin pound). $50
10 Ac-net cross section of
IL columns In square inches.
Ia As-cross section OF Longitude
% inai reinforcement in square
is (b) For columns reinforced
Is with longitudinal steel and with
Il spirally wound hopping, the safe
Is load shall be computed as fol.
% safe load Din pounds. $50
~ Ac-net cross section OF con.
% crete enclosed in hopping.
IS tudinal reinforcement and shall
IS not exceed so OF Ac.
~ Ah--314 da where d equals the
g diameter of the. hoop In inches.
10 p the pitch OF hoop p In inches
30 and a the cross section area OF
II the wire or rod forming the hoop
's in square inches, provided that
y All shall not be less than one
IS more ihan lM% OF Ac. also
IS that p shall never be more than
81 one-tenth G-10) the diameter OF
IS the hoop nor more than three
~ inches.
10 Where columns are subject TO
" loads OF known eccentrfcity. the
" combined stresses In the extreme
l3 fibre due to direct compression
"a and the bending moment shall |
10 not exceed the maximum COM |
vs. preston stress allowed In slabs
~ and beams.
rs The above stresses apply only |
40 to columns in which the ratio OF
80 the unsupported length to least |
II side Of diameter does not exceed |