Concrete Construction Part 59

Estimated proportionate charge for installing plant and holidays $0.28 ----- Grand total $1.66

Installing Plant.

Total.

Foreman 15-4/9 days $4.00 $61.78 Sub-foreman 1 day 3.00 3.00 Engineer 8-4/9 days 3.00 25.33 Carpenter 3 days 2.67 8.00 Watchman 42 days 2.00 84.00 Laborers 17-4/9 days 2.25 38.36 Laborers 149-8/9 days 2.00 299.78 Double team 10 days 5.00 52.50 Single team 6 days 2.00 12.00 Single team 1 day 3.50 3.50 Teaming (total) 53.00 Derrick and engine. 11-4/9 days 3.75 49.92 Rails and cars 8-2/9 days 0.40 3.29 Broken stone 7.05 tons 1.35 9.52 Egg coal .6 ton 6.25 3.75 Kerosene 30 gal. 0.11 3.30 Oil 4 gal. 0.25 1.00 Spikes 220 lbs. 0.05 11.00 ------- Total $723.03

The cost of the concrete work in the lower and upper layers can be still further detailed as shown below:

Lower Layer Concrete.

95.5 cu. yds., 1-2-6 concrete.

Materials: Rate. Per cu. yd.

Atlas cement 1.11 bbl. $1.35 $1.50 Sand .39 cu. yd. 1.10 0.43 Broken stone (.97 cu. yd.) 1.23 tons 1.35 1.66 Miscellaneous, plant, coal, etc. 1.28

Labor: Mixing and placing $2.09 Carpenter work on forms at $24.00 per M. .34 ----- Total per cu. yd. in place $7.30

Upper Layer Concrete.

129.2 cu. yds., 1-1-1-4 concrete.

Materials: Rate. Per cu. yd.

Atlas cement 1.37 bbl. $1.35 $1.85 Sand .24 cu. yd. 1.10 0.26 Stone dust (.25 cu. yd.) .32 ton 1.50 0.48 Broken stone (.75 cu. yd.) .96 ton 1.35 1.30 Lumber 0.31 M. ft. 21.00 0.65 Miscellaneous, plant, etc. 1.32

Labor: Mixing and placing 1.85 Carpenter work on forms at $21.00 per M. 0.66 ----- Total per cu. yd. in place $8.37

The following approximate labor costs are also given: Transporting, erecting and removing derrick, $260.85. Equivalent time: Foreman, 6 days; engineer, 4 days; laborer, 85 days.

Transporting, laying and removing track, $125.03. Equivalent time: Foreman, 4 days; laborer, 40 days.

Caring for dump and disposing of surplus by rough grading, $70.28.

Equivalent time: Foreman, 1 day; laborer, 33 days.

The total cost of the work was $3,503.66, divided up as follows:

Excavation $ 480.79 Lower layer concrete 614.15 Upper layer concrete 937.94 Back plaster 84.73 Surfacing 186.04 Asphalting 170.94 Back filling 103.27 Installing plant 716.03 Transportation and holidays 209.77 --------- Grand total $3,503.66

~LINING JEROME PARK RESERVOIR.~--The bottom of the reservoir that was lined covered 250 acres, and the concrete lining was 6 ins. thick. The lining was laid in alternate strips 16 ft. wide between forms set to grade. The concrete was mixed in 18 Ransome mixers provided with charging hoppers and mounted on trucks without boilers. Steam was supplied to the mixer engines from the boilers of the contractor's locomotives. One locomotive supplied steam for three or four mixers.

Tracks were laid in parallel lines across the reservoir bottom from 150 to 200 ft. apart. Sand and stone were hauled in on these tracks. The sand was dumped in stock piles at intervals; the stone was shoveled from the cars directly into the charging hopper and the sand was delivered by wheelbarrows to the same hopper. Four men shoveled the stone for each mixer. To deliver the concrete from the mixer to the work required six men with wheelbarrows. Two men leveled off the concrete discharged by the barrows and two other men floated the surface by means of a straight-edge spanning the 16-ft. strips and riding on the forms. By using a wet but not sloppy concrete and moving the straight-edge back and forth a good surface was secured. The gang mixing and placing consisted of 20 men for each mixer and 18 gangs laid approximately 1 acres per 10-hour day. The gang organization and wages were as follows:

Item. Per 10 hours.

4 men shoveling stone at $1.50 $ 6.00 2 men wheeling sand at $1.50 3.00 2 men delivering cement at $1.50 3.00 1 man dumping mixer at $1.50 1.50 1 man tending engine and water at $1.50 1.50 6 men wheeling concrete at $1.50 9.00 2 men spreading concrete at $1.50 3.00 2 men leveling concrete at $1.50 3.00 1 foreman 3.00 ------ Total per day $33.00

These costs do not include the fraction of a day's labor for fireman or the cost of fuel.

~RESERVOIR FLOOR, CANTON, ILL.~--The following costs are given by Mr. G.

W. Chandler for lining the bottom of a 16080-ft. reservoir with corners of 20-ft. radius and vertical brick sidewalls. A 1-3-7 crushed stone concrete was used; it was mixed by hand in batches of 2.7 cu. ft.

cement, 9 cu. ft. sand and 20 cu. ft. stone. The sand and stone were measured separately, the sand and cement mixed dry, then shoveled into a pile with the rock, well wetted, shoveled over again and then shoveled into wheelbarrows. The stone had 40 per cent. voids and the sand 30 per cent. voids. The lining was 10 ins. thick including a -in. coat of 1-2 mortar spread and worked smooth with a trowel. The cost per cubic yard of the lining in place was as follows:

0.856 bbl. cement at $2.50 $2.14 10.1 bu. sand (100 lbs. per bu.) at 5 cts 0.58 0.857 cu-yd-stone at $2.17 1.86 Labor, mixing and placing at 19 cts. per hr. 0.80 ----- Total $5.38

~RESERVOIR FLOOR, PITTSBURG, PA.~--The following methods and costs of laying a reservoir floor are given by Mr. Emile Low, M. Am. Soc. C. E., for the Hiland Reservoir constructed at Pittsburg, Pa., in 1884, by contract. There were 7,681 cu. yds. of concrete in the floor which was 5 ins. thick and laid on a clay puddle foundation.

Natural cement costing $1.35 per barrel was used. The broken stone varied in weight from 147 to 152 lbs. per cu. ft.; it was quarried and hauled 20 miles by rail and then unloaded into small cars and hauled mile to the reservoir. The cost of the stone per cubic yard delivered was:

Quarrying, per cu. yd. $0.45 Breaking, per cu. yd. 0.35 Transporting, per cu. yd. 0.50

Total $1.30

The sand was obtained on the site at the cost of excavation, or 1 cts.

per bushel.

The method of proportioning and mixing the concrete was as follows: Platforms 1016 ft. of 2-in. plank were laid on the puddle foundation and by these were set 541-ft. boxes on legs. Into these boxes 1 bbl.

of cement and 2 bbls. of sand were emptied and thoroughly mixed dry, then mixed with water to a thin grout. Five barrels of stone were placed on the platform and thoroughly wetted; the grout was then emptied over the stone and the two turned over three times with shovels. The concrete was rammed until the mortar flushed to the surface. The following costs cover various periods as follows:

Two Days Work (101 cu. yds.): Total. Per cu. yd.

27 laborers, 2 days, at $1.25 $72.90 $0.7217 1 foreman, 2 days, at $2.50 5.00 0.0495 ------ ------- Total $77.90 $0.7712

One Month's Work (1,302 cu. yds.): 642 days, laborers, at $1.35 $ 866.70 $0.6649 17 days, water boy, at $0.60 10.20 0.0078 22 days, foreman, at $2.50 55.00 0.0421 ------ ------- Total $931.90 $0.7148

Two Days Work (101 cu. yds.): Total. Per cu. yd.

27 laborers, 2 days, at $1.25 $72.90 $0.7217 1 foreman, 2 days, at $2.50 5.00 0.0495 ------ ------- Total $77.90 $0.7712

One Month's Work (1,302 cu. yds.): 642 days, laborers, at $1.35 $ 866.70 $0.6649 17 days, water boy, at $0.60 10.20 0.0078 22 days, foreman, at $2.50 55.00 0.0421 ------ ------- Total $931.90 $0.7148

Total Work (7,861 cu. yds.):

Quarrying stone $0.45 Transporting stone 0.50 Breaking stone 0.35 1-1/3 bbl. natural cement 1.80 8 bu. sand 0.10 Water 0.05 Labor mixing and laying at $1.25 0.75 Incidentals 0.05 ----- Total $4.05

The contract price was $6 per cu. yd.

[Ill.u.s.tration: Fig. 286.--Form for Constructing Silo.]

~CONSTRUCTING A SILO.~--The form construction shown in Fig. 286 was employed in building a silo 28 ft. high, 22 ft. 3 ins. interior diameter, and having 6-in. walls. The bottom of the silo was made 9 ins.

thick and set 2 ft. below the surface. The reinforcement consisted of ten 23/16-in. rings s.p.a.ced equally in the lower half and of woven wire fencing in the upper half. The iron rings were hoops removed from an old wooden silo. The concrete was a 1-6 mixture of Portland cement and sandy gravel. Figure 286 is a section through the forms. There were twenty T-shaped posts, which extended perpendicularly from the ground to a height of 28 ft., being secured at top and bottom by a system of guy ropes and posts. The rings, of which there are four, two inside and two outside, were built of weather boards with their edges reversed. Four thicknesses of board were used in each ring. The curbing consisted of 28-in. sticks 4 ft. long. Wedges driven between the vertical posts and the rings held the latter in place. When the forms were to be removed the wedges were knocked out and the rings sprung enough to permit the removal of the curbing. The rings were then pushed up and fastened in place for another section. The average rate of progress was one 4-ft.

section per day. The forms were filled in the afternoon and moved up the following forenoon. Five-foot sections could have been built just as readily.

The work was all done by farm laborers hired by the month and 100 man-days of such labor were required, excluding seven days work of a mason brus.h.i.+ng and troweling the surface. The cost of the work, not including the old hoop iron or the old lumber used in forms, was as follows:

Item. Total. Per cu. yd.

Cement $100.00 $2.62 Gravel and sand 35.00 0.92 1 20-rod roll of fencing 5.20 0.01 New lumber 18.00 0.47 100 days labor at $1.75 175.00 4.60 7 days mason troweling at $3.50 24.50 0.64 ------- ----- Total, 38.2 cu. yds. $357.70 $9.26

The external area of the silo is 1,950 sq. ft., which makes the cost of brus.h.i.+ng and troweling 1 cts. per sq. ft. There were about 2,300 ft. B.

M. of lumber used in the forms, or about 61 ft. B. M. per cu. yd. of concrete.

~GROINED ARCH RESERVOIR ROOF.~--The following data are given by Mr. Allen Hazen and Mr. William B. Fuller, in Trans. Am. Soc. C. E. 1904. The concrete was mixed in 5-ft. cubical mixers in batches of 1.6 cu. yds. at the rate of 200 cu. yds. per mixer day. One barrel of cement, 380 lbs.

net, a.s.sumed to be 3.8 cu. ft., was mixed with three volumes of sand weighing 90 lbs. per cu. ft., and five volumes of gravel weighing 100 lbs. per cu. ft. and having 40 per cent voids. On the average 1.26 bbls.

of cement were required per cu. yd. The conveying plant consisted of two trestles (each 900 ft. long) 730 ft. apart, supporting four cableways.

The cables were attached to carriages, which ran on I-beams on the top of the trestles. Rope drives were used to s.h.i.+ft the cableways along the trestle. Three-ton loads were handled in each skip. The installation of this plant was slow, and its carrying capacity was less than expected.

It was found best to deliver the skips of concrete to the cableway on small railway track, although the original plan had been to move the cableways horizontally along the trestle at the same time that the skip was traveling.