Concrete Construction: Methods and Costs by Gillette and Hill
CHAPTER XXIV.
4829 words | Chapter 80
MISCELLANEOUS DATA ON MATERIALS, MACHINES AND COSTS.
The following cost data comprise such miscellaneous items as do not
properly come in the preceding chapters. They are given not as including
all the miscellaneous purposes for which concrete is used but as being
such items of costs as were secured in collecting the more important
data given in preceding sections.
[Illustration: Fig. 303.--Device for Drilling Green Concrete.]
~DRILLING AND BLASTING CONCRETE.~--Concrete is exceedingly troublesome
material in which to drill deep holes, and this statement is
particularly true if the concrete is green. The following mode of
procedure proved successful in drilling 1½-in. anchor bolt holes 6 ft.
and over in depth in green concrete. The apparatus used is shown by Fig.
303, re-drawn from a rough sketch made on the work by one of the
authors, and only approximately to scale. The drill is hung on a small
pile driver frame, occupying exactly the position the hammer would
occupy in a pile driver, and is raised and lowered by a hand windlass.
By this arrangement a longer drill could be used than with the ordinary
tripod mounting and less changing of drills was necessary. A wide flare
bit was used, permitting a small copper pipe to be carried into the hole
with the drill; through this pipe water was forced under pressure,
carrying off the chips so rapidly that no wedging was possible. By this
device drilling which had previously cost over 25 cts. a hole was done
at a cost of less than 5 cts. a hole.
In removing an old cable railway track in St. Louis, Mo., holes 8 ins.
deep were drilled in the concrete with a No. 2 Little Jap drill, using a
1¼-in. bit and air at 90 lbs. pressure. A dry hole was drilled, the
exhaust air from the hollow drill blowing the dust from the hole keeping
it clean. The concrete was about 18 years old and very hard. Two holes
across track were drilled, one 10 ins. inside each rail; lengthwise of
the track the holes were spaced 24 ins. apart, or four pairs of holes
between each pair of yokes.
Common labor was used to run the drills and very little mechanical
trouble was experienced. Three cars were fitted up, one for each gang,
each car being equipped with a motor-driven air compressor, water for
cooling the compressors being obtained from the fire plugs along the
route. The air compressors were taken temporarily from those in use in
the repair shops, no special machines being bought for the purpose.
Electricity for operating the air compressor motors was taken from the
trolley wire over the tracks. The car was moved along as the holes were
drilled, air being conveyed from the car to the drills through a
flexible hose. Two drills were operated normally from each car. One of
the air compressors was exceptionally large and at times operated four
drills. The total number of holes drilled in the reconstruction of the
track was 31,000. The total feet of hole drilled was 20,700 ft.
With the best one of the plants operating two to three drills 30 8-in.
holes, or 20.3 ft. of hole, were drilled per hour per drill at a labor
cost of 2.7 cts. per foot.
For blasting, a 0.1-lb. charge of 40 per cent. dynamite was used in each
hole. A fulminating cap was used to explode the charge, and 12 holes
were shot at one time by an electric firing machine. The dynamite was
furnished from the factory in 0.1-lb. packages, and all the preparation
necessary on the work was to insert the fulminating cap in the dynamite,
tamp the charge into the hole and connect the wires to the firing
machine. In order to prevent any damage being done by flying rocks at
the time of the explosion, each blasting gang was supplied with a cover
car, which was merely a flat car with a heavy bottom and side boards.
When a charge was to be fired, this car was run over the 12 holes and
the side boards let down, so that the charge was entirely covered. This
work was remarkably free from accidents. There were no personal accident
claims whatever, and the total amount paid out for property damages for
the whole six miles of construction was $685. Most of this was for glass
broken by the shock of explosion. There was no glass broken by flying
particles. The men doing this work, few of whom had ever done blasting
before, soon became very skillful in handling the dynamite, and the work
advanced rapidly. The report made by the firing of the 12 holes was no
greater than that made by giant fire-crackers.
For the drilling and blasting the old rail had been left in place to
carry the air compressor car and the cover car. After the blasting, this
rail was removed and the concrete, excavated to the required depth. In
most cases the cable yokes had been broken by the force of the blast.
Where these yokes had not been broken, they were knocked out by blows
from pieces of rail. The efficacy of the blasting depended largely upon
the proper location of the hole. Where the holes had been drilled close
to the middle of the concrete block, so that the dynamite charge was
exploded a little below the center of gravity of the section, the
concrete was well shattered and could be picked out in large pieces.
Where the hole had been located too close to either side of the concrete
block, however, the charge would blow out at one side and a large mass
of solid concrete would be left intact on the other side. The total
estimated quantity of concrete blasted was 6,558 cu. yds., or 0.2 cu.
yd. of concrete per lineal foot of track. The cost of the dynamite
delivered in 0.1 lb. packages was 13 cts. per pound. The exploders cost
$0.0255 each.
The cost of drilling and blasting was as follows:
Item. Per mile. Per lin. ft. Per cu. yd.
Labor, drilling $ 89.76 $0.017 $0.085
Blasting labor and materials. 285.12 0.054 0.268
------- ------ ------
Total drilling and blasting. $374.88 $0.071 $0.353
[Illustration: Fig. 304.--Bench Monument, Chicago, Ill.]
The cost of blasting with labor and materials, separately itemized, was
as follows, per cubic yard:
Dynamite and exploders $0.192
Labor 0.076
------
Total $0.268
Two cubic yards of concrete were blasted per pound of dynamite.
~BENCH MONUMENTS, CHICAGO, ILL.~--The standard bench monuments, Fig. 304,
used in Chicago, Ill., are mostly placed in the grass plot between the
curb and the lot line, so that the top of the iron cover comes just
level with the street grade or flush with the surface of the cement
walk. The monument consists of a pyramidal base 6 ft. high and 42 ins.
square at the bottom, with a ¼-in.×2-ft. copper rod embedded, and of a
cast iron top and cover constructed as shown by the drawing. Mr. W. H.
Hedges, Bench and Street Grade Engineer, Department of Public Works,
Chicago, Ill., gives the following data regarding quantities and cost.
The materials required for each monument are: 1.78 cu. yd. crushed
stone, 0.6 cu. yd. torpedo sand, 1½ bbls. cement, 60 ft. B. M. lumber,
one ¼×24-in. copper rod, one top and cover. A gang consisting of 1
foreman, 4 laborers and 2 teams construct from one to three monuments
per day, the average number being two per 8-hour day. In 1906 the
average cost of the monuments was $24.12 each, based on above material
and labor charges.
[Illustration: Fig. 305.--Base for Wooden Pole.]
[Illustration: Fig. 306.--Mile Post, Chicago & Eastern Illinois Ry.]
~POLE BASE.~--Figure 305 shows a concrete base for transmission line poles
invented by Mr. M. H. Murray, of Bakersfield, Cal., and used by the
Power Transit & Light Co. of that city. These bases are molded and
shipped to the work ready for placing. They weigh about 420 lbs. each.
One base requires 37½ lbs. of 2×¼-in. steel bar, 40 lbs. of Portland
cement, 3 cu. ft. of broken stone or gravel and enough sand to fill the
form or mold, which is 10×10 ins. by 4½ ft. Unskilled labor is employed
in the molding and two men can mold ten bases per 8-hour day. The cost
of molding is as follows per base:
2 men at $2 per day $0.40
Brace irons per set 2.50
1-9 cu. yd. stone at $4.05 0.45
40 lbs. cement at 1½ cts. 0.60
Sand 0.15
-----
Total cost $4.10
Two men at $2 per day each set five bases in eight hours, making the
cost of setting 80 cts. per base. The bases were sunk to a depth of 3
ft. 3 ins. In many cases they were placed under poles without
interrupting service by sawing off the pole, dropping it into the
ground, placing the new base and setting the sawed-off pole on it and
bolting up the straps.
~MILE POST, CHICAGO & EASTERN ILLINOIS R. R.~--The dimensions of the post
are shown by Fig. 306. Each post weighs 498 lbs. They are made when
other concrete work is being done. The form is laid flat, with the molds
for the letters on the bottom, and bottom and sides are plastered with
mortar, which is backed up with a 1-1-2 stone concrete. The cost of the
post is given as follows:
¼ barrel of cement at $2 $0.50
267 lbs. crushed stone 0.01
133 lbs. sand 0.01
1-1/3 hours labor at 15 cts. 0.20
1/3 hour carpenter changing letters at 25 cts. 0.08
Coloring cement 0.02
-----
Total $0.82
~BONDING NEW CONCRETE TO OLD.~--Concrete which has set hard has a surface
skin or glaze to which fresh concrete will not adhere strongly unless
special effort is made to perfect the bond. Various ways of doing this
are practiced. The most common is to clean the hardened surface from all
loose material and give it a thorough wash of cement grout against which
the fresh concrete is deposited and rammed before the grout has had time
to set. Washing the old surface with a hose or scrubbing it with a brush
and water improves the bond, as does also the hard tamping of the
concrete immediately over the joint. Mortar may be used in place of
grout. The thorough cleansing of the surface is, however, quite as
essential as the bonding coat, in fact in the opinion of the authors it
is more essential. As a rule, a good enough joint for ordinary purposes
can be got by tamping the fresh concrete directly against the old
concrete, without grout or mortar coating, if the surface of the latter
is thoroughly cleaned by scrubbing and flushing. The secret of securing
a good bond between fresh concrete and concrete that has set lies
largely in getting rid of the glaze skin and the slime and dust which
forms on it. Washing will go far toward doing this. The glaze skin can
be removed entirely by acid solutions, but the acid wash must be flushed
free from the surface before placing the fresh concrete. Ransomite, made
by the Ransome Concrete Machinery Co., Dunellen, N. J., is a prepared
acid wash which to the authors' knowledge has given excellent success in
a number of cases. The glaze coat can also be removed by picking the
hardened surface, but the picking should be followed by washing to
remove all loose chips and dust.
~DIMENSIONS AND CAPACITIES OF MIXERS.~--In planning plant lay-outs it is
often desirable to know the sizes, capacities, etc., of various mixers
in order to make preliminary estimates. Tables XXII to XXXIII give these
data for a number of the more commonly employed machines. The Eureka,
the Advanced and the Scheiffler mixers are continuous mixers and the
others are batch mixers.
Table XXII--Sizes, Capacities and Weights of Advanced Mixers.
Cement Machinery Co., Jackson, Mich.
Height ground to hopper top 3' 6"
Width over all 3' 6"
Length over all on trucks 10' 6"
Capacity per hour, cu. yds. 25 to 75
Horsepower, engine 2
Weight:
On trucks, without power, lbs. 1,700
On trucks, steam engine 2,000
On trucks, gas engine 2,200
On trucks, steam engine and boiler 2,500
Table XXIII--Sizes, Capacities and Weights of Scheiffler Proportioning
Mixers. The Hartwick Machinery Co., Jackson, Mich.
Mixer Number. No. 2. No. 2½. No. 3.
Dimensions of hopper, ins. 55×33 53×33 60×40
Height, from ground to top of hopper, ins. 43 43 48
Width over all on trucks, ins. 46 46 46
Length over all on trucks, ins. 126 126 132
Hourly capacity in cubic yards 5-6 8 12-15
Horsepower required, gasoline engine 2 3 4
Horsepower required, steam engine. 3 4
Weights:
On trucks, without power, lbs. 2,400 2,900 3,300
On trucks, gasoline engine, lbs. 3,000 3,600 4,500
On trucks, steam engine, lbs. 2,800 3,330 4,000
On trucks, steam engine and boiler, lbs. 3,500 3,700 4,800
Table XXIV--Sizes, Capacities and Weights of Eureka Mixers.
Eureka Machine Co., Lansing, Mich.
-----------------------------------------------------------------
| | | |
Mixer Number | No. 81 | No. 82 | No. 83 |
-------------------------------|----------|----------|----------|
_ | | | |
| Sand | 18"×25½" | | |
Size hoppers, ins. | Cement | 17"×25½" | do | do |
|_ Stone | 30"×25" | | |
Height, ground to hopper top | 49" | 49" | 49" |
Width over all on trucks | 40" | 40" | 40" |
Length over all on trucks | 12'-9" | 10'-0" | 10'-0" |
Capacity per hour, cu. yds. | 10 to 18 | 10 to 18 | 10 to 18 |
Engine horsepower | 3 stm. | 3 stm. | 3½ gas |
Boiler horsepower | 4 | | |
Weight on trucks, no power | 1,980 | 1,980 | 1,980 |
Weight trucks steam engine | 2,800 | | |
Weight trucks gas engine | | | 2,300 |
Weight trucks, eng. and boiler | 3,000 | | |
-------------------------------|----------|----------|----------|
-----------------------------------------------------------------
| | |
Mixer Number | No. 84 | No. 25 | No. 23
-------------------------------|------------|----------|----------
_ | | |
| Sand | 18"×25½" | 18"×25½" | 18"×25½"
Size hoppers, ins. | Cement | 17"×25½" | 17"×25½" | 17"×25½"
|_ Stone | 30"×25" | |
Height, ground to hopper top | 49" | 49" | 49"
Width over all on trucks | 40" | 40" | 40"
Length over all on trucks | 10'-0" | 8'-0" | 8'-0"
Capacity per hour, cu. yds. | 10 to 18 | 10 to 18 | 2 to 4
Engine horsepower | 3 el. motr | Pulley. | Hand.
Boiler horsepower | | |
Weight on trucks, no power | 1,980 | 1,400 | 1,400
Weight trucks steam engine | | |
Weight trucks gas engine | | |
Weight trucks, eng. and boiler | | |
-------------------------------|------------|----------|----------
Table XXV--Sizes, Capacities and Weights of Snell Mixers.
R. Z. Snell Mfg. Co., South Bend, Ind.
Mixer Number. No. 0. No. 1. No. 2. No. 3.
Size batch, cu. ft. 3 7 11 24
Capacity per hour, cu. yds. 2½ 5 8 20
Speed revs. per min. 30 30 25 19
Weight on Skids:
With pulley, lbs. 480 800 900 2,000
With engine, lbs. 800 1,550 2,050 3,500
With eng. and boiler, lbs. 2,170 2,900 4,000
Weight on Wheels:
With engine, lbs. 1,100 2,200 3,450 4,700
With engine and boiler, lbs. 3,570 4,750 5,200
Engine:
Size cylinder, ins. 4×6 3½×4½ 4×5 5×6½
Rated horsepower 1½ 4 5 6
Boiler:
Size, ins. 24×60 26×60 30×60
Rated horsepower 5 6 8
Outside dimensions on skids 2'9"×4' 3'4"×5'6" 4'×6' 6'×9'
Total height on skids 3'8" 4'6" 5' 5'6"
Table XXVI--Sizes, Capacities and Horsepower of Ransome Mixers.
Ransome Concrete Machinery Co., Dunellen, N. J.
Mixer number. No. 1. No. 2. No. 3. No. 4.
Size batch, cu. ft. 10 to 14 20 30 40
Capacity per hr., cu. yds. 10 20 30 40
Speed, Revs. per min. 16 15 14½ 14
Weight on Skids:
Pulley or gear, lbs. 3,300 3,650 5,900 7,400
With engine, lbs. 4,600 5,050 7,700 9,250
With engine and boiler, lbs. 6,450 8,700 12,200 14,700
Weight on Wheels:
With engine, lbs. 5,100 5,550 8,200 9,750
With engine and boiler, lbs. 6,950 9,200 12,700 15,000
Engines:
Size cylinder, ins. 6×6 7×7 8×8 9×9
Rated horsepower 7 10 14 20
Boiler:
Size, ins. 36×69 42×75 42×87 48×93
Rated horsepower 10 15 20 30
Table XXVII--Sizes, Capacities and Horsepowers of Chicago Improved Cube
Mixers. Municipal Engineering and Contracting Co., Chicago, Ill.
Mixer No. No. No. No. No. No.
number. "Handy." 6. 11. 17. 22. 33. 64.
Size batch, cu. ft. 2½ 6 11 17 22 33 64
Capacity per hr., cu. yds. 5½ 13 24 40 50 70 120
Speed, revs. per min. 24 20 18 17 16 15 12
Weight on Skids:
Pulley or gear, lbs. 1,000 1,900 2,800 5,000 7,000 9,600 19,000
With engine, lbs. 2,500 3,600 6,100 8,200 12,000
With eng. and boiler, lbs. 3,100 4,300 7,800 10,000 16,000
Weight on Wheels:
With engine, lbs. 1,400 3,200 4,500 7,100 9,500 15,000
With eng. and boiler, lbs. 4,000 6,000 8,800 10,300 17,000
Engine:
Size cylinder, ins. 4×4 6×6 6½×7 7×8 8×9
Rated horsepower 2 3 6 8 12 15 30
Boiler, rated horsepower 4 8 10 15 18 35
Width over all 4'-5" 5'-10" 7'-1" 7'-8" 8'-6" 9'-8"
Length over all 4'-10" 6'-9" 8'-0" 8'-10" 10'-2" 13'-6"
Height bot. sill to
charging hopper 3'-4¼" 3'-5" 3'-10" 4'-7" 5'-0" 5'-9"
Additional height on
wheels 9-7/8" 1'-5-1/8" 1'-5-1/8" 6-3/8" 5½"
Table XXVIII--Sizes, Capacities and Horsepowers of Cropp Mixers.
A. J. Cropp, Concrete Machinery, Chicago, Ill.
Mixer number. No. 0. No. 1. No. 2. No. 3. No. 4.
Size batch, cu. ft. 7 to 8 10 13 16 20
Cap. per hr., cu. yds. 15 20 25 30 40
Speed, revs. per min. 12 10 10 10 10
Weight on Skids:
With engine, lbs. 1,375 1,650 1,700 1,975 2,100
With eng. and boiler, lbs. 2,575 2,950 3,000 3,775 3,900
Weight on Wheels:
With engine, lbs. 1,775 2,050 2,200 2,475 2,600
With eng. and boiler, lbs. 2,900 3,350 3,400 4,250 4,350
Engine:
Size cylinder, ins. 4×4 5×5 5×5 6×6 6×6
Rated horsepower 3 5 5 7 7
Boiler:
Size inside 24"×4' 24"×6' 24"×6' 30"×6' 30"×6'
Rated horsepower 4 6 6 9 9
Out. dimensions on skids 40" 40" 40" 48" 48"
Total height 50" 56" 56" 56" 62"
Height fr. ground on trucks:
Charging, ins. 20 20 20 20 20
Discharging, ins. 30 30 30 30 30
TABLE XXIX--SIZES, CAPACITIES AND HORSEPOWERS OF CHICAGO CONCRETE MIXERS.
Chicago Concrete Machinery Co., Chicago, Ill.
Number of mixer. No. 00. No. 0. No. 1. No. 2.
Standard charge in cu. ft. cement ½ 1 1 2
" " Sand 1½ 2½ 4 8
" " stone 3 5 8 16
Total unmixed batch in cu. ft 5 8½ 13 26
Mixed concrete per batch, loose in cu. ft. 3½ 6 9 18
Cubic yards of unmixed material per hour,
45 batches per hour 8 14 21 42
Cubic yards of mixed concrete per hour,
45 batches per hour 6 10 15 30
Minimum horsepower required 2 4 6 8
Revolutions of driving pulley per min 200 190 185 170
Revolutions of drum per min 20 18 15 13
Diameter and face of driving pulley 20×3½ 20×4½ 24×5½ 28×6½
Weight:
On skids with pulley, lbs. 1,550 2,150 2,900 4,850
On truck with pulley or gears, lbs. 1,800 2,550 3,500 5,150
On skids with st. engine only, lbs. ... 2,400 3,400 4,600
On truck with st. engine only ... 2,900 4,000 5,300
On skids with st. eng. and boiler, lbs. ... 2,800 4,700 6,000
On truck with st. eng. and boiler, lbs. 2,400 4,200 5,750 7,850
On skids with gasoline engine, lbs. 2,000 3,500 5,000 6,500
On truck with gasoline engine, lbs. 2,400 4,300 5,800 7,800
TABLE XXX--SIZES, CAPACITIES AND HORSEPOWERS OF KOEHRING MIXERS.
Koehring Machine Co., Milwaukee, Wis.
Mixer number. No. 0-B. No. 1-B. No. 2-B. No. 3-B.
Capacity per charge, in cu. ft 7 11 22 27
Capacity per hour in cu. yds 7 14 25 30
Horsepower, steam engine 4 6 8 10
Horsepower, steam boiler 5 8 10 14
Horsepower, gasoline engine 4 6 10 12
Horsepower, electric motor 5 6 7½ 10
Speed of drum 20 17 15 15
Speed of intermediate shaft 132 108 75 75
Weight of mixer on skids 1,800 2,800 5,200 5,500
Weight of mixer on skids, with steam eng. 2,300 3,550 6,500 7,000
Weight of mixer on skids, with steam
engine and boiler 3,300 5,000 8,000 9,300
Weight of mixer on skids, gasoline
engine and housing 3,000 4,400 7,500 8,600
Weight of trucks with pole 400 600 850 950
Weight of automatic loading bucket
complete 500 700 1,000 1,100
Weight of mixing through complete 200 250 400 400
TABLE XXXI--SIZES, CAPACITIES AND HORSEPOWERS OF SMITH MIXERS.
Contractors' Supply & Equipment Co., Chicago, Ill.
Mixer number. No. 0. No. 1. No. 2. No. 2½. No. 4. No. 5.
Stand. charge cu. ft. Cement 1 1 2 2 3 4
" " " " Sand 2½ 4 6 7½ 10½ 14
" " " " Stone 5 8 12 15 21 28
Total unmixed per batch,
cu. ft. 8½ 13 20 24½ 34½ 46
Mixed material per batch
(loose), cu. ft. 6 9 13½ 16½ 22 30
Cubic yards mixed per
hour, up to 9 20 30 39 46 62
Power required--H.P. 4 6 8 10 15 19
Revs. per minute of
driving pulley 218 180 173 162 160 125
Diameter and face of
driving pulley, ins. 20×4½ 24×5½ 28×5½ 28×6½ 36×6½ 48×7½
Weight on skids with
pulley only, lbs. 1,740 2,500 3,600 4,400 6,200 7,900
Weight on truck with
pulley or gears, lbs. 2,200 3,650 4,750 5,500 7,400 ....
Weight on truck with
steam eng. & boil., lbs. 3,750 5,600 7,200 8,600 11,400 ....
Weight on truck with
gasoline engine, lbs 4,000 5,100 7,400 9,300 .... ....
TABLE XXXII--SIZES, WEIGHTS AND CAPACITIES OF POLYGON MIXER.
Waterloo Cement Machinery Co., Waterloo, Iowa.
Mixer number. No. 4. No. 5. No. 6. No. 7.
Maximum charge, cu. ft. 6 10 12 16
Cubic yards mixed per day (10 hrs.) up to 60 190 130 180
Weight on skids with pulley (approx.) 1,600 2,200 3,500 4,000
Weight on skids with steam engine and
boiler (approx.) 3,100 3,900 5,500 6,200
Weight on skids with gasoline engine
(approx.) 2,900 3,900 5,100 5,700
Weight on trucks with steam engine and
boiler (approx.) 3,600 4,600 6,000 7,000
Weight on trucks with gasoline engine
(approx.) 3,400 4,650 5,700 6,750
~DATA FOR ESTIMATING THE WEIGHT OF STEEL IN REINFORCED
CONCRETE.~--Architects' and engineers' plans record the steel used in
reinforced concrete in various ways. Sometimes complete schedules of
shapes, dimensions and weights of the various reinforcing elements are
drawn up and submitted to bidders with the plans. In such cases the
estimating is usually a simple problem for the contractor. In other
cases the amount of steel that will be required is stated as a
percentage of the volume of the concrete. In still other cases the
detail drawings merely show the number, location and dimensions of the
reinforcing bars, stirrups, etc., and the contractor has to compile from
them his own schedule of quantities. The following tables and discussion
will aid the contractor in making his estimates. Before proceeding with
these data, however, the authors would strongly advise that to
facilitate rapid estimating the contractor should keep accurate records
of all reinforced concrete structures in such form as to show the
percentages of steel used. In doing this, however, he should be careful
to separate the foundations, etc., which are not reinforced from the
superstructure which is reinforced. A reinforced concrete arch bridge,
for example, usually rests on piers and abutments which are not
reinforced. Do not lump together all the concrete in recording the
weight of reinforcement used, but separate the reinforced arch from the
unreinforced portions.
~Method of Computing Weight from Percentage of Volume.~--In a cubic yard
of concrete there is 1 per cent. of 27 cu. ft. or 0.27 cu. ft. of steel
if the reinforcement is 1 per cent. Now a cubic foot of steel weighs 490
lbs., but for all practical purposes we can call it 500 lbs. Hence
reinforced concrete containing 1 per cent. of steel has 0.27 × 500 = 135
lbs. per cubic yard. Table XXXIII has been computed in this manner;
knowing the price of steel it is a matter of simple multiplication to
estimate from the table the cost of steel for any percentage of
reinforcement.
~Weights and Dimensions of Plain and Special Reinforcing Metals.~--Steel
for reinforcement is used in the shape of plain round and square bars,
deformed bars, woven and welded netting and metal mesh of various sorts.
Tables XXXIV to XXXVII show the weights, dimensions, etc., of these
various metals.
TABLE XXXIII--SHOWING WEIGHT OF STEEL PER CUBIC FOOT AND PER CUBIC YARD OF
CONCRETE FOR VARIOUS PERCENTAGES OF REINFORCEMENT.
Per cent Lbs. steel Lbs. steel
of steel. Per cu. ft. Per cu. yd.
0.20 1.00 27.0
0.25 1.25 33.8
0.30 1.50 40.5
0.35 1.75 47.3
0.40 2.00 54.0
0.45 2.25 60.8
0.50 2.50 67.5
0.55 2.75 74.3
0.60 3.00 81.0
0.65 3.25 87.5
0.70 3.50 94.5
0.75 3.75 101.3
0.80 4.00 108.0
0.85 4.25 114.8
0.90 4.50 121.5
0.95 4.75 128.3
1.00 5.00 135.0
TABLE XXXIV--WEIGHTS OF ROUND AND SQUARE BARS OF DIMENSIONS COMMONLY
USED FOR REINFORCING CONCRETE.
Thickness or Weight of square Weight of round
diameter in inches bars. Lbs. per ft. rods. Lbs. per ft.
1/16 0.013 0.010
1/8 0.053 0.042
3/16 0.119 0.094
¼ 0.212 0.167
5/16 0.333 0.261
3/8 0.478 0.376
7/16 0.651 0.511
½ 0.850 0.668
9/16 1.076 0.845
5/8 1.328 1.043
11/16 1.607 1.262
¾ 1.913 1.502
7/8 2.608 2.044
1 3.400 2.670
1-1/8 4.303 3.380
1¼ 5.312 4.172
1½ 7.650 6.008
1¾ 10.404 4.178
2 13.600 10.68
TABLE XXXV--DIMENSIONS AND WEIGHT OF EXPANDED METAL.
Mesh, Sectional area sq. Weight, lbs.
inches. ins. per ft. width. per sq. ft.
Standard ½ 0.209 0.74
Standard ¾ 0.225 0.80
Standard 1½ 0.207 0.70
Standard 2 0.166 0.56
Standard 3 0.083 0.28
Light 3 0.148 0.50
Standard 3 0.178 0.60
Heavy 3 0.267 0.90
Extra heavy 3 0.356 1.20
Standard 3 0.400 1.38
Standard 3 0.600 2.07
Old style 4 0.093 0.42
Standard 6 0.245 0.84
Heavy 6 0.368 1.26
TABLE XXXVI--DIMENSIONS AND WEIGHT OF KAHN RIB METAL.
Size Section area Weight per
No. per ft. width sq. ins. sq. ft. lbs.
2 0.54 2.13
3 0.36 1.43
4 0.27 1.08
5 0.22 0.87
6 0.18 0.72
7 0.15 0.62
8 0.14 0.55
TABLE XXXVII--WEIGHTS OF DEFORMED BARS OF DIMENSIONS COMMONLY USED FOR
REINFORCED CONCRETE.
Size. Weight, lbs. Area. Size Weight, lbs. Area
ins. per ft. sq. ins. ins. per ft. sq. ins.
[Illustration: Ransome Twisted Bar.] [Illustration: New Style Corrugated Bar.]
¼ 0.212 0.063 ¼ 0.24 0.06
½ 0.85 0.25 ½ 0.85 0.25
5/8 1.32 0.319 5/8 1.33 0.39
¾ 1.91 0.563 ¾ 1.91 0.56
7/8 2.6 0.765 7/8 2.60 0.77
1 3.4 1.000 1 3.40 1.00
1¼ 5.3 1.563 1¼ 5.30 1.56
[Illustration: Diamond Bar.] [Illustration: Universal Corrugated Bar.]
½ 0.85 0.25 ¼×1 0.73 0.19
5/8 1.33 0.39 5/16×1¼ 1.18 0.32
¾ 1.91 0.56 3/8×1-3/8 1.35 0.41
7/8 2.60 0.76 3/8×1¾ 1.97 0.54
1 3.40 1.00 3/8×2 2.27 0.65
1¼ 5.31 1.56 3/8×2½ 2.85 0.80
--No. 1 Mill-- [Illustration: Thatcher Bulb Bar.] --No. 2 Mill.--
¼ 0.16 0.047 ... ... ...
½ 0.61 0.18 ½ 0.58 0.17
5/8 0.95 0.28 5/8 0.92 0.27
¾ 1.39 0.41 ¾ 1.34 0.39
7/8 1.87 0.55 7/8 1.79 0.53
1 2.42 0.71 1 2.32 0.68
1¼ 3.74 1.10 1¼ 3.55 1.04
1½ 5.30 1.56 1½ 5.20 1.53
1¾ 7.07 2.08 .... .... ....
2 9.02 2.65 .... .... ....
[Illustration: Monolith Bar.] [Illustration: Twisted Lug Bar.]
0.4 0.55 0.25 ¼ 0.222 0.625
½ 0.85 0.32 ½ 0.87 0.250
... .... .... 5/8 1.35 0.3906
... .... .... ¾ 1.94 0.5625
0.8 2.18 0.64 7/8 2.64 0.7656
1 3.37 1.00 1 3.45 1.00
... .... .... 1¼ 5.37 1.5625
1½ 7.75 2.25 1½ 7.70 2.25
[Illustration: Cup Bar]
3/8 0.48 ....
½ 0.86 ....
5/8 1.35 ....
¾ 1.95 ....
7/8 2.65 ....
1 3.46 ....
1-1/8 4.38 ....
1¼ 4.51 ....
~RECIPES FOR COLORING MORTARS.~--The following recipes for coloring cement
mortar have been found reliable; the weights given being weight of
coloring matter per bag of cement and for a 1-2 mortar:
_Brown Stone_: 4 to 5 lbs. brown ochre or ½ lb. best quality roasted
iron oxide.
_Buff Stone_: 4 lbs. yellow ochre.
_Red Stone_: 5 lbs. raw violet iron oxide.
_Bright Red Stone_: 5½ to 7 lbs. English or Pompeiian red.
_Blue Stone_: 2 lbs. ultramarine blue.
_Dark Blue Stone_: 4 lbs. ultramarine blue.
_Slate_: Lamp black ½ lb. light slate; 4 lbs. dark blue slate.
_Light Terra Cotta_: 2 lbs. Chattanooga iron ore.
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