John C. (John Cresson) Trautwine.

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quent plastering, etc. Cone, free from large agg, to be placed next the mold,
and prest back from mold by means of a flat shovel, inserted betw cone and
mold (mold sprinkled with water, Kit), cone rammed with an iron rammer,
lower face 2" X 6", AH, BR ; finish by working gravel back from face by
means of forks, Hb ; or shovels, FP ; faces rubbed smooth, TR, Hb ;
with a piece of wood or soft stone, TR ; voids filled up with mortar, Hb.
TR, CR; plastering permitted only for an occasional and accidental
cavity where the plastering is not apt to be disturbed by frost, R. See
p 1193, U 79. 1 : 3 Port cem mortar, placed simultaneously with backing,
CR. For wall, 1 : 2 Port cem mortar, very dry, 1 }/ thick, TR.

67. For exposed faces, forms to be removed before cone has hardened;
surf (1) rubbed with mortar of 1 yol Port cem, 2 vols sand, applied with a
burlap swab and brushed down with a plasterer's brush, or (2) rubbed with
stiff wire brush and a thin coat of neat Port cem grout, brushed down with
plasterer's brush, NO, Co ; smooth finish of sides produced by thoro
ramming against inside surfs of molds, SE.

68. Surfs, not built against forms, screeded and troweled to smoothness,
NO.

69. Voids or other imperfections, appearing upon removal of forms, to
be corrected at expense of contractor, who shall remove and replace unsatis-
factory work if reqd, F.

70. For floors and roof of mixing tank. Stiff mortar, of 1 vol
Port, 1 vol sharp stone screenings to pass %" ring, free from dust, loam, etc, 1"
deep, laid before cone has initial set. Screeded, floated and troweled to
smooth surf. Covered and sprinkled 3 days, Co.

71. Promenades and tops of parapets finished with a layer of
mortar > M" thick, consolidated with the cone "by superimposing heavy
planks 4" thick and rammirjg them with 40-lb cast iron rammers until their
ends are in contact with the ends of the molds," SE.

72. For piers, pedestals, abutments. Surfs exposed to air or
water, 1 W Port cement mortar, 1 cement, 2 sand, carried up simultane-
ously with the cone, 10 or 11" in depth at a time, by means of %" steel
plate forms, 12" wide, 4 to 5 ft long, placed around the work, 1 W from the
forms, and blocked out every 12" by wooden blocks, the ends of the plates
lapping slightly, WH.

73. For inverts, 1 cem, 2 sand, not more than %" thick, laid at same
time as cone, I^v.

74. Moldings, cornices, etc. Plastic mortar placed against finely
constructed molds, as cone is being laid; no exterior plastering permitted,
SE, T & 1 ; no plastering to be done unless expressly permitted, F.

75. Top finish. Cone brought up to 3 %" from reqd elevation; while
this is still unset and plastic, 3" of finer cone added, tamped and kneaded
to form a monolith with the underlying cone; then y<? of 1 : 3 (1 : 2, AH)
cem mortar added and worked down to reqd grade by rubbing with a long
wooden straight-edge, AH, BR.

76. Coping*. While cone base is still soft, unset and adhesive, mortar
(to be 1" thick when finished) spread, leveled off and beaten with wooden
battens or mauls; floated with wooden float and smoothed with plasterer's
trowel; covered with boards or tarpaulins until hard set; then covered with
sand; to be kept damp several days, FP ; mortar, < 1" thick, of 375 Ibs
Port cem to 10.5 cu ft sand; tamped in place on top of rammed cone before
the latter has begun to set; raked with straight-edge, rubbed with wooden



CONCRETE SPECIFICATIONS. 1193

For abbreviations, symbols and references, see p 947 Z.

floats and finished with plasterer's trowel, CR ; 1 : 2 Port cem mortar, 1*
thick, TR ; surf formed by working the stones back from face, Hb.

77. Granitoid surface finish for tops of piers, pedestals and abuts;
1 part Port, 2 parts clean coarse granite sand or fine granite screenings, 3
parts granite chips, passing y% iron ring. Finished with a floated surf. WM .

78. Water-proofing. Heavy coat of semi-liquid mortar 1 part cem,
% part slaked hme, 3 parts sand. This coat to be given a smooth finish.
When this has set hard, add a heavy coat of pure cem grout, CS.

79. Plastering with cement. None permitted on exposed faces,
AH, CS. Inside faces of spandrel walls, covered by fill, to be well
dampened and plastered with mortar of 1 cem : 2.5 sand, CS. See p
1192, U 66.

Artificial stone.

80. (a) For fine moldings, etc. ftfolds plastered with semi-liquid
mortar, 1 cem, 2 fine sharp sand, backed with earth-damp cone 1:2:4,
or 1 cem to 6 gravel passing %" ring. Cone backing rammed in thin
layers, (b) For plain flat surfaces. Cone rammed in mold. Mold
removed. Exposed surfs floated to smooth finish with mortar as in (a).
No body of mortar to be left on face. Use only enough to fill pores and give
smooth finish, CS.

Strength, etc, required.

(Strengths, etc, in Ibs / D", unless otherwise stated.)

81. IJltimate comp, after hardening for 28 days, < 2000, tin, Mh.

82. lilt shear corresponding to 2000 comp, 200, Un.

Maximum allowable loads.

83. For static loads upon a 1 : 6 Port cem cone.

Max allowable load

Ibs / D"t

Compressn, cone surface > loaded area 0.325.8*= 650

in columns, length > 12 diams 0.225.8 = 450

with longitudinal reinfmt only 0.225. s = 450

hooped 0.270. s = 540

, with 1 to 4 % long'l bars . . .0.325.* = 650
with structural steel col units thoro-

650
650

adjacent to supports, (E constant) 0.375.* = 750

Pure shear (no comp normal to shearing surf; reinfmt tak-
ing the normal tension) 0.060.* = 120

Shear, combined with equal comp 0.162.* = 325

Adhesion, plain bars 0.040 . s = 80

drawn wire 0.020.* = 40

JC.

84. Compression. See also t 146, p 1198.

A, exclusive of temp stresses,

B, including stresses due to temp changes of 40 F

In arches for bridges, Ibs / D": A B

for highways and electric railways 500 600

for steam railways .400 500

CS.

85. On first-class Port cem cone, with agg properly graded:

1 : 6 or less, 60,000 Ibs / sq ft = 417 Ibs / CT;

1 : 5 or less, in beams or slabs 500

"In case a richer cone is used, this stress may be increased with the ap-
proval of the commissioner to not more than" 600 Ibs / n", Ms.

* * = ult comp strgth in Ibs / D" at 28 days when tested, under labora-
tory conditions, in the form of cyls 8" diam, 16" long, of same consistency as
used in the field.

t When s = 2000 Ibs / Q*.



WllJll OUlU^CUlCn 3UGC1 WJl U&UWB ljLl\Ji\J~

ly encasing cone core 0.325.*

Rupture modulus (elas mod, E, constant) 0.325.*



1194 CONCRETE.

For lists of Specifications for Concrete, see pp 1184, 1185.

86. Portland, 1:2:4.. . .230 Ibs / D",

1:2:5 208

Rosendale or equal,

1:2:4 125

1:2:5 Ill " X Y.*

87. Portland, Ibs / D". Mix, 1:2:4 1 : 2.5 : 5 1:3:6

machine-mixed 400 350 300

hand-mixed 350 300 250

Natural 150

Cinder, 700 ;

Port, in reinfd cone; direct, 0.2 X ult; in bending, 0.35 X ult. Ch.

88. Port, direct, 350 Ibs / Q"; in reinfd work, 350 Ibs / D" simultane-
ously with 6000 Ibs / D" tension in steel, Un.

89. Port, direct, 350; in bending, 500, Mb.

Aggregate

90. Port, Stone or gravel Slag Cinder

In bending 600 400 250 Ibs / D*

Direct, in cols

length > 15 diam 500 300 150

In hooped cols, 1000 Ibs / D" on area within hooping, Ph.

1:2:4 1:2:5 1:3:6

Port 700 650 600 Ibs / D"

Nat 400 ... ... "It.

91. Tension, Ibs / D".

A, exclusive of temp stresses,

B, including stresses due to temp changes of 40 F.

A B

In reinforced arches 50 75

In reinforced slabs, girders, beams, etc CS.

On diagonal plane, 0.02 X ult comp strgth, Ch.

92. Shear, Ibs / D".

75, CS ; 50, Mh ; 60 when uncombined with comp upon the same plane
"unless the bldg commissioner with the consent of the board of appeal
shall fix some other value," Ms; stone or gravel cone, 75; slag, 50; cinder,
25, Ph.

Elastic modulus.

93. 1,500,000 Ibs / Q", CS.

Adhesion.

94. See p 1111, and p 1196, U 113.

Safety factors.

ultimate load

Safety factor = r. -3-^ -3-.

allowed load

95. At end of 1 mo, in subways and girder bridges for highways and
electric . rys, also bldgs, roofs, culverts, sewers, 4; in subways and girder
bridges for steam rys, 5, CS.

Port, in reinfd cone, comp, direct, 5; in beams, 1/0.35; Ch.

In reinfd beams, 1 for dead load, plus 4 for live load, = 5;

In iron or steel in latticed or open work cols, beams or girders, encased in
cone which extends < 2" beyond metal (with no allowance for the cone), 3.
L.

Reinforcement.

96. Bars, unpainted, but free from scale, rust and grease, O.

97. Shape. Plain round or square, or corrugated, LiV ; plain or
twisted, XO ; deformed, AH ; twisted or deformed, Bu ; Square machine-

* Corresponding with loads proposed by C. C. Schneider, Trans, A S C E,
Vol 54, Jun '05, p 384. On p 493 Mr. Schneider proposes, instead, for Port
cem cone only:

per sq ft per sq inch

1:2:5.. .. 20 tons = 40,000 Ibs 278 Ibs.

1:2:4.. ..25 " = 50,000 " 347 ".



CONCRETE SPECIFICATIONS. 1195

For abbreviations, symbols and references, see p 947 I.

twisted, Co ; Ransome twisted square preferred, F; Ransoine or equal, II b ;
Thacher bar, CS ; square, twisted cold, or Johnson corrugated bar; in
Johnson bar, net section = that reqd, by the plans, for twisted bars; plain
bars to be used in comp only, Ci.

98. Twisted bars.

Size, ins ........ M H Yz % % % 1 1H 1

Twists per ft ..... 12 8 5 3.5 2.5 2 1.75 1.5 1.5, NO. Co;

6 ............... 1.5 ...... , Ci.

One turn in 5 to 7 times nominal size, F.

Twisted uniformly by machinery; min cross sec area to vary not more
than 2.5 %, NO, Co.

99. Round, corrugated, etc, bars to have same agg net sec area
as square or twisted bars, NO.

Requirements.

100. Iron and steel "to meet the 'Manufacturers' Standard Specfns,'
revised Feb 3, '03," Ph. See pp 873 a, b.

101. Steel. Mfr and hardness. Medium open-hearth, NO, Bu,
Co, Ci ; mild, I^v ; soft or medium, CS.



102. Ultimate tensile strength, in thousands of Ibs / Q". 52

to 62, F ; 54 to 64, Un, Mh : medium, 50 to 65, Cl,a ; medium, 60 to
68, CS ; soft, 54 to 62, CS ; 55 to 65, L,v, T & T ; < 55, NO ; 57 to 65,
Co,a ; 60 to 70 before twisting, Co,b ; 60 to 70, Bu.

103. lilt comp strength.

Mixture . 1:1:2 1:1.5:3 1:2:4 1:2.5:5 1:3:6

lbs/Q" = 2900 2400 2000 1750 1500

n = E S /E C = 10 12 15 18 20

ill.

104. Fracture, silky, uniform in color and texture, Co.

105. Elastic limit < half ult tensile strgth, G.

106. Elastic modulus, 30,000,000 Ibs/LT, CS.

107. Ratio, n, of elastic moduli. - ~* - ^ m d for rted

E C elas mod for cone

n = 12, Mh. "If not shown by direct tests," in beams and slabs, n = 15;
in cols, n = 10, Ms; with ult comp strgth = 2000 Ibs / D", n = 18, Un.
Stone or gravel cone, n 12; slag, n = 15, Ph ; cinder, n = 30, Ph, Ch.

108. Elongation, %, minimum, in 8", 25, F, L.V, NO, Co,a; 22,



Co,b, Ci,a; 20, Un, Mh; soft, 25; medium, 22, CS ; rTT T & T.

tensile strgth

109. Bending test. Cold, F, I,v, Bu, CS ; hot, cold or quenched,
NO, Co,a ; 180 about a diam = the thickness of the bar, F, NO, Bu,
Co, CS; (before deforming, F); about a diam = twice the thickness of
the bar, L.y ; (after deforming, F) ; soft steel, flat, CS ; cold, 90 over a
diam = twice the thickness of the bar in steel > %" diam; over a diam
= 3 X thickness of bar in steel > %" diam, Ch.

Maximum stresses allowed in steel.
Stresses in Ibs / Q" unless otherwise stated.

110. Tension, 16,000, Mh, Ph, .1C; (iron, 12,000, Ph); one-third
elas lira, but not over 18,000, Ch ; mild, 12,000; medium, 15,000; high-
carbon, 18,000, L.

111. Shear, 10,000, Mh; 12,000, Ch.

.. Co,np = co mpin conc X

"In arches, the steel ribs under a stress not exceeding 18,000 Ibs per square
inch must be capable of taking the entire bending moment of the arch with-
out aid from the cone, and have flange areas of < the 150th part of the total
area of the arch at crown. The actual stress when imbedded in and acting
in combination with cone shall not exceed 20 times the allowed stress on
the cone."

79



1196 CONCRETE.

For lists of Specifications for Concrete, see pp 1184, 1185.

"In slabs, girders, beams, floors, and walls, subjected to transv stress, the
steel shall be assumed to take the entire tensile stress without aid from the
cone, and shall have an area sufficient to equal the comp strgth of cone
composed of 1 part Port cem, 3 parts sand, and 6 parts of broken stone, of
the age of 6 mos."

"In walls or posts subjected to comp only, no allowance will be made for
the strgth of imbedded steel, which will be used only as a precaution against
cracks due to shrinkage or changes of temp."

"In tanks, the imbedded steel under a stress not exceeding 15,000 Ibs / D"
shall be capable of taking the entire water pres without aid from the cone, "
CS.

Elongation in service not more than 0.2 %, Ch.

113. Adhesion between steel and concrete. Assumed > al-
lowed shear on cone, Mh, Ms : < shear on cone, Un ; in stone or gravel
cone, 50 Ibs / D"; slag, 40; cinder, 15, Ph.

114. In 1 : 2 : 4 cone, max, Ibs / D":

on plain round or square bars, structural steel 70

high carbon steel 50

on plain flat bars, ratio of sides > 2 : 1 . . . 50

on twisted bars, < 1 twist in 8 diams 80

on specially formed bars,

0.25 X ult adhesion as determined by test; max 100 Ch.

115. When the allowed adhesion is exceeded, "provision
must be made for transmitting the strgth of the steel to the cone," Un, Mh,
Ph.

116. Length and lapping.

Longitudinal bars not less than 3O ft, if possible, IJv.
In beams, rods of single length, if possible, NO, Co, i.
If lapped

Size of rod, ins X % Y* % % VB 1 1 1 A IX

Lap, ins 6 10 13 18 20 22 26 30 32 NO.

6 9 12 15 18 20 22 24 27 Co.

Lap = 25 diams of rod, Bu.

Lap < 20 X diam of rod, < 1 foot, Ci.

In parallel rods, joints staggered, Bu, Ci.
Ends, not less than 2" from any surf, L,y.

Rods extend to extreme edges of unfinished surfs.
" within 1" of finished surfs. Co.

Floor rods extend 4" beyond face of wall supporting the floor;

Beam " " < 8" beyond face of wall supporting the floor,
NO, Ci. See Clearance, below.

117. Protection. If work is interrupted, bars, already placed, must
be protected, as with canvas or tarred paper. Ends, projecting for a con-
siderable time, to be painted with heavy coat of neat cem grout, F, IiV.

Permit.

118. Complete detailed plans and specfns, giving composition of cone, to
be filed with the Commissioner of Bldgs, Ch, Un, Mh, Ph.

Issue of permit does not involve acceptance of constr, Ch. For tests
required, see pp 1194-5.

Clearance. See also Iffl 116, 134, 144, 149.
Distance, t, between steel and surf of cone.

119. In cols, beams and girders, t < 1 Yz", Ch, Ms 5 in slabs,
t < Yz" < diam of bar, Ch; t < n", Ms; t < 1.5 X diam of bar, JC.

Axis of rods dist from outside of cone < diam of rod, CS.
For fireproof buildings, see ^ 120-128.

Clear dist betw bars < 1.5 X max sectional dimension of bar,
Ch, JC. Clear dist betw two layers of bars, < %", JC.

120. For fireproof buildings (til 120-128), reinfd cone constr not
approved "unless satisfactory fire and water tests shall have been made
under the supervision of this Bureau," Mh.

May be accepted if designed as prescribed in code, provided that :

(1) Agg shall be "hard-burned broken bricks, or terra-cotta, clean furnace



CONCRETE SPECIFICATIONS. 1197

For abbreviations, symbols and references, see p 947 L

clinkers entirely free of combustible matter, clean broken stone, or furnace
slag, or clean gravel, together with clean siliceous sand, if sand is reqd to
produce a close and dense mixture ; " Un. (The other codes quoted specify
fewer permissible varieties of agg.) Agg to pass M in sq mesh, Ch ; 1" ring,
and 25 % of agg > half max size, Ph.

(2) Min thickness, t, of cone, surrounding the reinfg members, shall be
as follows, where d = diam parallel to t :

121. When d > M", t = I"; when d > M", t = 4 d. In any case t

> 4"; t < thickness required for structural purposes plus a, a = 1" in cols
and girders, a = M" in floor slabs "but this shall not be construed as in-
creasing the total thickness of protecting cone as herein specified." Un.

122. In girders and columns, t = 2"; in beams, t = 1>"; in floor
slabs, t = l" JC.

123. In monolithic cols, the outer 1 H" .to be considered as protective
covering, and not included in effective section, JC.

124. For beams 'and girders; on bottom, t = 2"; on sides, t =
1 H". Under slab rods, t = I". In cols, t = 2", Ch, Ph.

125. "If a supplementary metal fabric is placed in the cone surrounding
the reinfg, simply for holding the cone, the thickness of cone under the re-
infg may be reduced by M". such fabric shall not be considered as reinforcg
metal," Ch.

126. On floor and roof beams, t = 1"; on floor and roof girders, and on
beams carrying masonry, on top, t = 1"; elsewhere, 2"; on cols, carrying
only floors, t = 3"; on cols built into or carrying walls, 4", Ms.

127. Cinder concrete, for fireproof constr, t same as for stone cone;
for slow-burning or mill constr, on cols, t = 2"; " on beams, girders and other
structural steel or iron members," t = 1 M". Covering to have "metal
binders or wire fabric imbedded in and around" such members; binders,
if of wire, not less than No. 8, not less than 16" apart, Ch.

128. Corners of cols, beams and girders, to be beveled or rounded, JC.

Columns.

129. Columns must be allowed < 2 hrs for settlement and shrinkage
before girders are constructed over them, JC.

130. " Rules for the computation of reinfd cone cols may be formu-
lated from time to time by the bldg commissioner with the approval
of the board of appeal," Ms.

131. Concrete and steel assumed to shorten "in the same
proportion", Ms.

132. Cone and steel stressed in ratio, n, of their elastic moduli,
JC.

133. Rods tied together at intervals sufficiently short to prevent
buckling, Ms. See 1 136.

134. Outer 1 H" to be considered as protective covering and not included
in effective section, JC.

Reinforced columns.

Ij = length; d = diameter or least side.

135. Reinfd cone may be used for cols when L > 12 d, Ch, Un, Mb;

> 15 d, JC; and where cross section area < 64 D", Ch. If L > 15 d,
allowable stress to be decreased proportionally, Ph.

136. Requirements. Rods to be tied together at intervals
not more than d, Un, Mh, Ph ; not more than 12 d, not more than 18", Ch.
See U 133.

137. Longitudinal rods not considered as taking direct compres-
sion, Ph.

138. Combined cross section area of comp rods > 3 % of cross
sec area of col, Ch.

139. When comp rods are not reqd, combined cross sec area of rods to
be < 0.5 % of cross sec area of col; not less than 1 D", Ch.

140. Least dimension of smallest rod to be not less than J^", Ch.



(3)
(4)



1198 CONCRETE.

For lists of Specifications for Concrete, see pp 1184, 1185.

141. Rods to extend into the col above or below, lapping the rods there
sufficiently to develop the stress in the rod by the allowed unit for adhesion,
Ch.

142. Eccentric or transverse loading. Max fiber stress, in-
cluding (1) direct comp, (2) bending due to direct comp, (3) eccentricity
and (4) transverse load, not more than allowable cornp stress. Eccentric
load "shall be considered to affect eccentrically only the length of col ex-
tending to the next point below at which the col is held securely in the
direction of the eccentricity," Ms.

143. A column, monolithic with or rigidly attached to a beam
or girder, must resist, in addition to direct loads, a moment = max
unbalanced moment in the beam or girder at the col, Ch.

144. Hooped columns. Cone may be stressed to 25 % of ult
strgth, provided

(1) Cross sec area of vert reinfmt < area of spiral reinfmt, > 5 % of
area within hooping ;

(2) Percentage of spiral hooping < 0.5, > 1.5 ;

Pitch of spiral hooping uniform and > 0.1 X diam of col, > 3";
Spirals so secured to verticals, at every intersection, as to main-
tain form and position;
(5) Spacing of verticals > 9", > Y% circumference of col within hooping.

Hooping "may be assumed to increase the resistance of the cone equiv-
alent to 2.5 X the amount of the spiral hooping figured as vert reinfmt."
Cone, outside of hooping, not considered as part of effective col sec, Ch.

145. "The working stresses will be a subject for special consideration
by the Commissioner of Bldgs," Un.

146. Allowed unit compression = 1000 lbs/D" of area within
hooping, Ph.

147. Percentage of long'l rods and spacing of hoops to be such that the
cone may develop this stress with a safety factor of 4, Ph.

148. "Hoops or bands not to be counted upon directly as adding to the
strgth of the col," JC.

149. Clear spacing of bands and hoops > 0.25 X diam of enclosed col, JC.

150. Structural steel reinforced columns. Cone may be
subjected to M ult stress, provided (1) cross sec area of steel is not less than
1 Q"; (2) spacing of lacing or battens not more than least width of col, Ch.

Beams and floors.

151. The common theory of beams is applicable. Un, Ch,
Mh, Ph.

152. The steel is assumed to take all the direct tensile stresses,

Ij, Un, Ch, Ms, Mh, Ph. Tensile stress in cone to be considered in
calculating deflections, JC.

153. The stress-stretch curve of cone in comp is assumed to be a

straight line, Ch, Ph. n, = E f /E e , = 15; for deflections, n = 8 to 12, JC.

154. At 2000 Ibs/D" extreme fiber stress, this curve may be taken as
(a) a straight line; (b) a parabola, with axis vert, and vertex on neutral
axis of beam; or (c) an empirical curve, enclosing an area M greater than
if curve were a straight line, and with cen of grav at same height as that of
area in (b), Un.

155. Stresses. A load, = 4 X the total working load, stresses the
steel to its elas lim, and the cone to '2000 Ibs/D", Un. Design "based on
the assumption of a load 4 times as great as the total load, Ph. (Total
load = ordinary dead load plus ordinary live load, Un, Ph.)

156. The adhesion, betw cone and steel, is assumed to be sufficient
to make them act unitedly, Un, Ch, Mh, Ph.

157. Exposed metal not considered in figuring strgth, Un, Ch, Ph.

158. Span = dist c to c of bed plates or other bearings, Ms, JC.
If beam is fastened to side of a col, span is measured to cen of col, Ms.
Span > (clear span + depth of beam or slab), JC.



CONCRETE SPECIFICATIONS. 1199

For abbreviations, symbols and references, see p 947 I.

159. Shrinkage and thermal stresses to be provided for by
introduction of steel, Ch, Ph. "Initial stress in the reinfmt, due to con-
traction or expansion in the cone, may be neglected," JC.

160. When the shear developed exceeds the allowed limit for cone,
steel must be introduced to take the excess, IJn, Mil. Ph, JC.

161. Allowable values for shearing stresses: lbs/D"

(a) With horizontal bars only 40;

(b) With part of the hor reinfmt in the form of bent-up bars,

"arranged with due respect to the shearing stresses" >60;

(c) With thoro reinfmt for shear >120,

JC.

Under (c), cone may be taken as carrying % of the shear; the remaining
% being carried by bent rods or stirrups (preferably both) carrying their
share within a hor dist = depth of beam, JC 1 .

162. Longitudinal spacing of stirrups or bent rods > 0.75 X depth of
beam, JC.

163. Cement finish, added to the tops of slabs, beams and girders,
not to be included in figuring strgth unless laid integrally with the
rough cone," and to be allowed no greater unit stress than that on the rough
cone, Ch.

164. Web reinforcement. "Where the vertical shear, measured
on the sec of a beam or girder, betw the centers of action of the hor stresses,

> 0.02 X the ult direct comp stress/Q", web reinfmt shall be supplied,
sufficient to carry the excess. The web reinfmt shall extend from top to
bottom of beam and loop or connect to the hor reinfmt. The hor reinfmt,
carrying the direct stresses, shall not be considered as web reinfmt,'' Ch.

165. Steel in the compression sides of beams and girders.
"When steel is used in the comp side of beams and girders, the rods shall
be tied in accordance with requirements of vert reinfd cols with stirrups
connecting with the tension rods of the beams or girders," Ch.

166. "When steel or iron is in the comp sides of beams the proportion
of stress taken by the steel or iron shall be in the ratio of the mod of elas
of the steel or iron to the mod of elas of the cone; provided, that the rods
are well tied with stirrups connecting with the lower rods of the beams;"
Ph.

167. Where slabs are used with girders and beams, the
girders and beams are treated as T'-beams, a portion of the slab acting as


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