DUST PREVENTION AND ROAD PRESERVATION, 1915. 29 
Table 30. — Materials and cost data for surface-treatment experiments on Falls Road. 
1 
1 
o © *»• 
Q 
Description. 
Quantity of mate- 
rials (per square 
yard). 
Cost per square 
yard. 
1 
1 
Bituminous material. 
Length of 
section. 
Area of 
section. 
Bitumi- 
nous ma- 
terial. 
Gravel. 1 
Bitumi- 
nous ma- 
terial. 
Gravel 
(hauling 
included). 
1 
2 
3 
5 
...... 
1 
Asphalt petroleum (cold) 
Residual asphaltic petroleum 
(hot) 
Feet. 
4,575 
4,386 
7,941 
5,718 
5,880 
Sq. yds. 
7,625 
7,310 
13,235 
9,530 
9,800 
Gallon. 
0.525 
.739 
.423 
.538 
.596 
Cu. yds. 
0.0149 
.0164 
.0151 
.0150 
.0150 
Cents. 
2.63 
5.54 
4.02 
4.57 
4.77 
Cents. 
3.84 
4.25 
3 
4 
<> 
Coal-tar preparation (cold) 
Refined water-gas tar (cold). . . 
3.53 
3.67 
3.65 
Description. 
Cost per square yard. 
Total cost. 
1 
1 
Bituminous material. 
Clean- 
ing sur- 
face. 
Heat- 
ing bi- 
tumi- 
nous 
mate- 
rial. 
Haul- 
ing and 
apply- 
ing hot 
mate- 
rial. 2 
Spread- 
ing 
gravel. 
Roll- 
ing. 
Miscel- 
lane- 
ous^ 
Per 
square 
yard. 
Per 
mile, 
15-foot 
road. 
1 
2 
Asph 
Resid 
(ho 
Coal-1 
Retin 
Refin 
altic petroleum (cold) 
ual asphaltic petroleum 
Cents. 
0.05 
.05 
.01 
.04 
.08 
Cents. 
0.41 
Cents. 
0.23 
.37 
.12 
.24 
.32 
Cents. 
0.32 
.71 
.38 
.55 
.86 
Cents. 
0.05 
.10 
.04 
.04 
.02 
Cents. 
0.65 
.68 
.38 
.52 
.51 
Cents. 
7.77 
12.11 
8.48 
9.63 
10.21 
$683.76 
1,065.68 
746. 24 
847. 44 
898. 48 
3 
4 
;ar preparation (cold) 
ed water-gas tar (cold) 
ed coal tar (hot) 
1 2,500 pounds equals 1 cubic yard. 
2 Hauled to road in distributor. 
3 General expense and superintendent. 
INSPECTION REPORT. 
The following report describes the condition of the experiments 
on the Falls Road on the date of last inspection, April 27, 1916. 
Experiment No. 1. — At the time of the inspection the surface did 
not appear to carry a distinct mat or carpet and the bituminous 
treatment was worn very thin and showed a tendency to crumble, 
even on warm days. It is probable that a re-treatment will be neces- 
sary early in the spring as the aggregate of the macadam shows quite 
generally throughout the central portion of the road. 
Experiment No. 2. — This section has a black, leathery mat which 
is easily marked by the calks of passing horses, but irons out under 
the wheels so that there is no indication of "picking up" or dis- 
integration. In a few places additional gravel had to be spread to 
prevent bleeding, and it is probable that more top-dressing will be 
required as soon as hot weather prevails. At the present time very 
little stone shows in the mat. 
Experiment No. 3. — The gravel used for top-dressing plainly shows 
everywhere on this section and an excess still remains along the 
sides. The mat is a hard, stone-filled carpet, practically unbroken, 
and shows no signs of failure anywhere. In general this was the 
best appearing section of the road at the time of the inspection. 
