Concrete Construction Part 63

TABLE x.x.xI--SIZES, CAPACITIES AND HORSEPOWERS OF SMITH MIXERS.

Contractors' Supply & Equipment Co., Chicago, Ill.

Mixer number. No. 0. No. 1. No. 2. No. 2. No. 4. No. 5.

Stand. charge cu. ft. Cement 1 1 2 2 3 4 " " " " Sand 2 4 6 7 10 14 " " " " Stone 5 8 12 15 21 28 Total unmixed per batch, cu. ft. 8 13 20 24 34 46 Mixed material per batch (loose), cu. ft. 6 9 13 16 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. 204 245 285 286 366 487 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 x.x.xII--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 quant.i.ties. 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 x.x.xIII 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 x.x.xIV to x.x.xVII show the weights, dimensions, etc., of these various metals.

TABLE x.x.xIII--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 x.x.xIV--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 0.212 0.167 5/16 0.333 0.261 3/8 0.478 0.376 7/16 0.651 0.511 0.850 0.668 9/16 1.076 0.845 5/8 1.328 1.043 11/16 1.607 1.262 1.913 1.502 7/8 2.608 2.044 1 3.400 2.670 1-1/8 4.303 3.380 1 5.312 4.172 1 7.650 6.008 1 10.404 4.178 2 13.600 10.68

TABLE x.x.xV--DIMENSIONS AND WEIGHT OF EXPANDED METAL.

Mesh, Sectional area sq. Weight, lbs.

inches. ins. per ft. width. per sq. ft.

Standard 0.209 0.74 Standard 0.225 0.80 Standard 1 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 x.x.xVI--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 x.x.xVII--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.

[Ill.u.s.tration: Ransome Twisted Bar.] [Ill.u.s.tration: New Style Corrugated Bar.]

0.212 0.063 0.24 0.06 0.85 0.25 0.85 0.25 5/8 1.32 0.319 5/8 1.33 0.39 1.91 0.563 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 1 5.3 1.563 1 5.30 1.56

[Ill.u.s.tration: Diamond Bar.] [Ill.u.s.tration: Universal Corrugated Bar.]

0.85 0.25 1 0.73 0.19 5/8 1.33 0.39 5/161 1.18 0.32 1.91 0.56 3/81-3/8 1.35 0.41 7/8 2.60 0.76 3/81 1.97 0.54 1 3.40 1.00 3/82 2.27 0.65 1 5.31 1.56 3/82 2.85 0.80

--No. 1 Mill-- [Ill.u.s.tration: Thatcher Bulb Bar.] --No. 2 Mill.-- 0.16 0.047 ... ... ...

0.61 0.18 0.58 0.17 5/8 0.95 0.28 5/8 0.92 0.27 1.39 0.41 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 1 3.74 1.10 1 3.55 1.04 1 5.30 1.56 1 5.20 1.53 1 7.07 2.08 .... .... ....

2 9.02 2.65 .... .... ....

[Ill.u.s.tration: Monolith Bar.] [Ill.u.s.tration: Twisted Lug Bar.]

0.4 0.55 0.25 0.222 0.625 0.85 0.32 0.87 0.250 ... .... .... 5/8 1.35 0.3906 ... .... .... 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 ... .... .... 1 5.37 1.5625 1 7.75 2.25 1 7.70 2.25

[Ill.u.s.tration: Cup Bar]

3/8 0.48 ....

0.86 ....

5/8 1.35 ....

1.95 ....

7/8 2.65 ....

1 3.46 ....

1-1/8 4.38 ....

1 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 lb. best quality roasted iron oxide.

_Buff Stone_: 4 lbs. yellow ochre.

_Red Stone_: 5 lbs. raw violet iron oxide.

_Bright Red Stone_: 5 to 7 lbs. English or Pompeiian red.

_Blue Stone_: 2 lbs. ultramarine blue.

_Dark Blue Stone_: 4 lbs. ultramarine blue.

_Slate_: Lamp black lb. light slate; 4 lbs. dark blue slate.

_Light Terra Cotta_: 2 lbs. Chattanooga iron ore.