DUST PREVENTION AND ROAD PRESERVATION, 1915. 
Table 1. — Surface construction. 
Ex- 
peri- 
ment 
No. 
Stone. 
Bituminous material. 
By penetration method. 
By mixing method. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
Sandstone... 
do 
do 
Fluxed native asphalt A 
Oil-asphalt X 
Fluxed native asphalt A. 
Oil-asphalt X. 
do 
Gneiss 
do 
do 
do 
Fluxed native asphalt A 
Oil-asphalt X 
Oil-asphalt X. 
Fluxed native asphalt A. 
Oil-asphalt Y. 
Fluxed native asphalt B. 
Gravel 
do 
do 
do 
Oil-asphalt Y. 
Section II 
Trap 
do 
do 
Oil-asphalt X 
Fluxed native asphalt A 
Fluxed native asphalt A. 
Oil-asphalt. 
do 
Section III 
Granite 
do 
do 
do 
Fluxed native asphalt A 
Oil-asphalt X 
Oil-asphalt X. 
Fluxed native asphalt A. 
Work was begun under contract February 25, 1915, and the project 
was finished December 6, 1915. A total of 20 working days was lost, 
owing to unfavorable weather and other causes. Of the total cost of 
$65,694.45 Alexandria County paid $33,696.21. 
General Features of the Project. 
Equipment. — The equipment available consisted of a steam shovel, 
1,000 feet of industrial-railway track and cars, a pile driver, a me- 
chanical scarifier, a semiportable road asphalt-mixing plant, three 
500-gallon portable asphalt-heating kettles, a 10-ton macadam roller, 
an 8-ton tandem roller, an Emerson steam pump, 2 gasoline pumps 
and pipe, two 5-ton motor trucks, dump-bottom wagons, drag 
scrapers, plows, pouring pots, and hand tools. 
Excavation. — Nearly all the excavation was done by steam shovel, 
and material was hauled to the fills by dump wagons. The industrial 
railway was not used to any extent. All fills were built in layers ap- 
proximately 1 foot in thickness and rolled where possible. Side-hill 
slopes under new fills were thoroughly plowed. Slopes in cuts were 
finished 1 :1 and on fills 1J:1. The road was constructed 16 feet wide, 
with 4-foot shoulders, and the side ditches were excavated 19 inches 
below the grade of the road. The crown was f inch to 1 foot on all 
sections. Of the total of 28,575 cubic yards of necessary excavation, 
27,478 cubic yards occurred on section I between stations —1+61 
and 153 +00. 
"Drainage. — Subdrainage, culverts, and catch basins were built 
where needed. Ungalvanized corrugated-metal pipe culverts were 
placed as indicated in Table 2. 
