Cost at Ottawa, Canada.—The method and cost of constructing 1,326 ft. of concrete curb and gutter at Ottawa, Ont., are given in some detail by Mr. G. H. Richardson, Assistant City Engineer, in the annual report of the City Engineer for 1905. We have remodeled the description and rearranged the figures of cost in the following paragraphs.
The concrete curb was built before doing any work on the roadway, and the first task was the excavation of a trench 2½ ft. wide and averaging 1 ft. 8 ins. in depth through light red sand. On the bottom of this trench there was placed a foundation of stone spalls 8 ins. thick; in width this foundation reached from 3 ins. back of the curb to 6 ins. beyond the front of the water table. The curb was made 5 ins. thick and ran from 10 ins. to 5½ ins. in height, and the water table was 14 ins. wide and 4 ins. thick, with a fall of 1¼ ins. from front to back. The concrete used was a mixture of 1 Portland cement, 3 sand, 3⅝-in. screened limestone, and 4 2-in. stone. It was deposited in forms and tamped to bring the water to the face and then smoothed with a light troweling of stiff mortar.
The forms were constructed by first setting pickets and nailing to them a back board 2 ins. thick and 12 ins. wide and a front board 2 ins. thick and 6 ins. wide. The concrete for the water table was deposited in this form in sections and brought to surface by straight edge riding on wooden strips nailed across the form and properly set to slope, etc. After the water table had been troweled down and brushed a 1×10-in. board was set to mold the front face of the curb. This board was sustained by small "knee frames" made of three pieces of 1×2-in. stuff, one conforming to the slope of the water table and long enough to extend beyond the front of the 2×6-in. front board, a second standing plumb and bearing against the 1×10-in. face board, and the third forming a small corner brace between the two former to hold them in their proper relative positions. The 1×10-in. face board, etc., was separated from the 2×12-in. back board by a 5-in. block at each end, and then braced by the knee frames every 3 or 4 ft. In this way it was possible to bring this 1×10-in. board into perfect line by moving the knee braces in or out, and when correct nailing them to the 2×6-in. front board. The 1×10-in. face board being in position and braced and lined, the curb material was thoroughly tamped in, and when ready was troweled and brushed on the top, a small round being worked onto the top front corner with the trowel.
Expansion joints were provided for by building into the curb every 12 ft., a piece of ⅜-in. boiler plate, which was afterward withdrawn and the joint filled with sand and faced over. As soon as the concrete had set sufficiently the face board was taken down and face of curb finished and brushed, the fillet between curb and water table being finished to 2½ ins. radius. Circular curb and gutter of same construction was built at each corner, ½-in. basswood being used for forms, instead of 2×1-in. lumber.
In addition to the actual construction of curb and gutter the cost given below includes the cleaning up of the street, spreading or removal of all surplus material from excavation, and the extension of all sidewalks out to the curbs at the corners. It was also necessary to maintain a watchman on this work, which duty, under ordinary circumstances, would be done by the general watchman. The total length built was 1,326 ft., of which 1,209 ft. is straight and 117 ft. curved to a 12-ft. radius.
The rates of wages paid were $2 for horse and cart, $1.65 for watchman, and an average of $1.90 per day for labor, including foreman; all for nine hours' work per day. The working force consisted of foreman, finisher, handy man. four concrete men, and three laborers.
The labor cost of the work was as follows:
| Item. | Total. | Per ft. cts. | P. C. of total. |
| Excavation and setting boards | $ 88.90 | 6.7 | 30 |
| Laying stone foundation | 43.30 | 3.3 | 14 |
| Concreting | 61.30 | 4.6 | 20 |
| Finishing | 45.15 | 3.4 | 15 |
| Carting | 9.85 | 0.76 | 3 |
| Watchman | 25.00 | 1.89 | 8 |
| Clearing up | 13.60 | 1.04 | 4 |
| Extras (sidewalk extensions) | 17.23 | 1.31 | 6 |
| ——— | —— | — | |
| Total | $304.33 | 23.00 | 100 |
The cost of materials for curb and foundation were as follows:
| Total. | Per lin. ft. cts. | |
| 171.112 tons spalls | $102.93 | 7.76 |
| 42 tons 2-in. stone | 41.16 | 3.09 |
| 30.8 tons ⅝-in. stone | 42.57 | 3.21 |
| 33,000 lbs. cement | 161.70 | 12.19 |
| 24 cu. yds. sand | 19.20 | 1.45 |
| ——— | —— | |
| Total | $367.56 | 27.70 |