74 
BULLETIN 724, U. S. DEPARTMENT OF AGRICULTURE. 
type of road, and since it lias already been described in the office pub- 
lications on brick road construction, it will not be discussed further 
here. 
COST OF CONCRETE FOUNDATIONS. 
In estimating the cost of a concrete foundation it is necessary to 
consider the materials and the labor separately. Table 12 shows the 
quantities of the different materials required to build 100 linear feet 
of foundation 6 inches thick for the various proportions of mix ordi- 
narily used in foundation construction. In preparing the table the 
percentages of voids in the coarse aggregate have been assumed as 
35 and 45, respectively, for well-graded gravel and average crushed 
stone. The sand is assumed to be moderately well graded and each 
barrel of cement is assumed to have a volume of 4 cubic feet. 
Table 12. — Showing quantities of materials required fori eubic yard of concrete. 
PROPORTION. # 
Sand. 
Coarse 
aggre- 
gate. 
Coarse aggregate to be ^veil- 
graded gravel or equivalent. 
Coarse aggregate to be average crushed 
stone or equivalent. 
Cement. 
Cement. 
Sand. 
Coarse 
aggre- 
gate. 
Cement. 
Sand. 
Coarse 
aggre- 
gate. 
Width 
(6 inches 
thick). 
1 
2 
2i 
4 
5 
Barrels. 
1.38 
1.13 
Cu. yds. 
0.41 
.42 
Cu. yds. 
0.82 
.84 
Barrels. 
1.51 
1.24 
Cu. yds. 
0.45 
.45 
Cu. yds. 
0.90 
Feet. 
1 
.92 

QUANTITIES. 
1 
f 23. 00 
6.83 
13.67 
25.17 
7.50 
15. 00 
9 
35. 78 
10-63 
21.26 
39.15 
11.67 
23. 34 
14 
1 
2 
4 
\ 46. 89 
12.15 
24.30 
44. 74 
13. 33 
26.67 
16 
46.00 
13.67 
27.33 
50.33 
15.00 
30.00 
18 
{ 51. 11 
15.18 
30.37 
55.93 
16.67 
33.33 
20 
f 18. 83 
7.00- 
14.00 
20.67 
7.67 
15. 33 
9 
29.30 
10.89 
21.78 
32.15 
11. 93 
23.86 
14 
1 
21 
5 
\ 33. 48 
12.44 
24.89 
36.74 
13.63 
27.26 
• 16 
37.67 
14.00 
2S.0O 
41.33 
15. 33 
30. 67 
18 
{ 41.85 
15.55 
31.11 
45.93 
17.04 
34.08 
20 
f 17. 83 
7.83 
13.17 
19.33 
8.67 
14.33 
9 
27.75 
12.19 
20:48 
30. OS 
13.48 
22.30 
14 
1 
3 
5 
\ 31. 70 
13.93 
23.41 
34.37 
15. 41 
25.48 
16 
35.67 
15. 67 
26.33 
38.67 
17.33 
28.67 
18 
1 39. 63 
17.41 
29.26 
42.96 
19.26 
31.85 
20 
f 16.17 
7.17 
14.33 
17.67 
7.83 
15.67 
9 
25. 15 
11.15 
22.30 
27.49 
12.19 
24. 37 
14 
1 
3 
6 
[ 28. 74 
13.74 
47.48 
31.41 
13. 93 
27. 85 
16 
32.33 
14.33 
28.67 
. 35.33 
15.67 
31.33 
18 
[ 35. 93 
15.93 
71.86 
39.26 
17.41 
34.82 
20 
3 
7 
f 14.67 
22- 82 
\ 26. 07 
29.33 
[ 32. 59 
6.50 
10.11 
11.56 
13.00 
14.44 
15. 17 
23.60 
26.96 
30.33 
33.70 
9 
14 
I 
16 
18 
20 
PROPORTIONS. 
1.07 
.97 
.83 
0.47 
.43 
.39 
0.79. 
.86 
:91 
1.16 
1. 06 
0.S6 
.94 
