DUST PREVENTION" AND ROAD PRESERVATION, 1915. 



Table 1.— Surface construction. 





Ex- 

 peri- 

 ment 



No. 



Stone. 



Bituminous material . 





By penetration method. 



By mixing method. 



Section I 



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 



Fluxed native asphalt A 



Oil-asphalt X 







Oil-asphalt X. 



Fluxed native asphalt A. 



Oil-asphalt Y. 





do 1 





Gravel 





do . 



Fluxed native asphalt B. 

 Refined tar. 





do 







do 





Oil-asphalt Y. 



Section n 



Trap 



do 



do 



Oil-asphalt X 





Fluxed native asphalt A 



Fluxed native asphalt A. 

 Oil-asphalt. 





do 





apotinn TTT 



Granite 



do 



do 



Fluxed native asphalt A 



Oil-asphalt X 













Oil-asphalt X. 





do 





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 Coxmty 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 aU 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 roUed where possible. Side-hill 

 slopes under new fills were thoroughly plowed. Slopes in (^uts were 

 finished 1 :1 and on fills 1^: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. 



Draiv/ige. — Subdrainage, culverts, and catch basins were built 

 where needed. Ungalvanized corrugated-metal pipe culverts were 

 placed as indicated in Table 2. 



