26 



BULLETTX 249, U. S. DEPARTMENT OF AGKICTTLTUKE. 



erally varies from 40 to 75 cents, while grading in solid rock may 

 sometimes cost as much as $1.50 per cubic yard. It is well to con- 

 sider the cost of the rough grading entirely apart from the cost of 

 the pavement, The drainage structures, however, may be consid- 

 ered together with the grading. The cost of these varies over such a 

 wide range that no attempt will be made to discuss them here. 



The cost of shaping and rolling the subgrade after the rough grad- 

 ing is completed is generally from 5 to 10 cents per square yard. 

 This cost should be included with the other items which make up 

 the cost of the pavement proper. 



The cost of the concrete depends largely on the cost of the ma- 

 terials of which it is composed. These materials, delivered on the 

 work, vary in cost according to the location of the work and the 

 freight rates about as follows : Cement, from SI to $2.50 per barrel ; 

 sand, from $0.60 to $2 per cubic yard; and broken stone or gravel, 

 from $0.60 to $2 per cubic yard. The cost of mixing, placing, and 

 finishing the concrete ordinarily varies from $0.60 to $1.25 per cubic 

 yard, and depends on the efficiency of the organization and on 

 whether the mixing is done by hand or machine. For machine mix- 

 ing and labor at $0.20 per hour, $0.80 appears to be a fair average 

 cost per cubic yard, including all overhead and incidental charges. 

 The cost of constructing forms, contraction joints, etc., including the 

 materials, is usually from $0.03 to $0.10 per square yard. "Where sim- 

 ple types of joints and forms are used this cost should not exceed 

 about $0.05 per square yard of pavement. 



The following actual cost records taken from the 1912 annual re- 

 ports of the Illinois State Highway Commission should prove help- 

 ful in estimating the cost of new work. These records do not appear 

 to include any charges for the use of tools and machinery, but such 

 charges should properly be included in preparing an estimate. 



Table II. — Cost of concrete roads in Illinois. 



Labor and supplies. 



Superintendence 



Slia ping subgrade 



Loading and hauling sand and stone 



M b; ing and placing concrete 



Watchman and miscellaneous labor 



Cost of sand and stone 



Cost of cement 



Expansion joints 



Coal and oil for mixer, and miscellaneous 



supplies 



Forms and other lumber 



Filling expansion joints next to curbs 



Reinforcing steel 



Excaval ion 



Trimming shoulders 



Project No. 1. 



Totals. 



SI 40. 00 



307. 11 



267. 34 



414.63 



110.26 



1,017.63 



1,647. 15 



48.67 



30. 75 

 35.00 

 45.18 



Totals 3, 964. 02 



Per 

 square 

 yard. 



t0. 028 



.061 

 . 053 

 .083 

 .022 

 .204 

 .309 

 .010 



.006 

 .007 

 .010 



Project No. 2. 



Totals. 



S157. 50 

 108.70 

 7"\ 05 

 700. 58 

 I3L 16 

 74LO0 

 2,307.90 

 112.40 



25.00 

 31.75 



100.00 

 591.73 



•/:>; 



5, 803. 07 



Per 

 square 

 yard. 



$0. 0220 

 .0153 

 .1120 

 .0986 

 .(list 

 . 1050 

 .3246 

 .0156 



.0034 

 .0047 



.0140 

 .0840 



.8176 



Project Xo. 3. 



Totals. 



5202. 00 

 232.44 

 603. 50 

 644.25 

 383. 75 

 1,622,01 

 1..-..M. 17 

 206.74 



119.19 

 18,33 



•Jll.:> 



5,794.76 



Per 

 square 

 yard. 



SO. 03fil 

 .0415 

 . 107s 

 .1150 

 .0686 

 . 2897 



.0369 



. 0213 

 .0033 



.0378 



1.0352 



