16 BULLETIN 407, U. S. DEPARTMENT OF AGRICULTURE. 



No. 2 of the mixing plant at station 95 + 00, and some bituminous 

 material was lost in the long haul. The analysis of the fluxed native 

 asphalt is shown in Table 8. 



Experiment No. 17. — Bituminous Macadam (Penetration Method). Granite 

 WITH Fluxed Native Asphalt A. 



Location: Station 192+00 to station 200+00. 



Total length: 800 feet. 



Total area: 1,422.2 square yards. 



The base of this section consisted primarily of an old water-bound 

 trap macadam road, which was scarified and reshaped. It was 

 necessary to widen the old road an average of 2 feet. The added 

 width of base was of "1^-inch" granite, which was also used to 

 supplement a few weak spots in the old macadam base. The entire 

 base was thoroughly rolled and compacted by a 10-ton roller. No 

 binder was used. 



The method of laying the surface in this experiment was exactly 

 similar to that of experiment No. 13. The materials used, however, 

 were fluxed native asphalt A and '' IJ-inch" granite. The properties 

 of the asphalt are shown in Table 8, and the physical properties and 

 mechanical analysis of the granite are shown in Tables 4 and 5, 

 respectively. The mechanical analysis of the chips used is shown in 

 Table 7. 



Experiment No. 18. — Bituminous Macadam (Penetration Method). Granite 



with Oil-Asphalt X. 



Location: Station 200+00 to station 208+89. 



Total length: 889 feet. 



Total area: 1,580.4 square yards. 



The base of this experiment from stations 200 + 00 to 201+00 was 

 similar to that described for experiment No. 17, From stations 

 201 +00 to 208 + 89 the old macadam was entirely removed to revise 

 the grade, and a base of "IJ-inch" granite was laid to a loose depth 

 of 6 inches and thoroughly compacted by a 10-ton niacadam roller 

 without the addition of any binder. 



In other particulars this experiment was exactly similar to experi- 

 ment No. 17, except that an oil-asphalt X was used with properties 

 as shown in Table 8, instead of fluxed native asphalt. 



Experiment No. 19. — Bituminous Macadam (Mixing Method). Granite 

 with Oh- Asphalt X. 



Location: Station 215+28 to station 225+10. 



Total length: 982 feet. 



Total area: 1,728 square yards. 



The base of this experiment was an old water-bound trap-rock mac- 

 adam road, rather badly out of shape. It was scarified and reshaped 

 from station 219 + 00 to the end of the experiment. From stations 



