62 BULLETIN 407, U. S. DEPARTMENT OF AGRICULTURE. 
scarifying a section about 40 feet long so as to include the entire 
Chevy Chase Club entrance, then using the scarified material as a 
base and laying a new wearing surface of bituminous concrete of the 
analysis given in Table 61. A sample of the fluxed native asphalt 
used in the mixture gave the analysis shown in Table 62. At the 
time of inspection this intersection was in perfect condition. The 
total area of the intersection, as rebuilt, was 100 square yards, and 
the work was done by contract at a cost of $150. 
Table 61. — Analysis of bituminous concrete used in resurfacing a portion of section 6. 
Per cent. 
Bitumen soluble in CS 2 (total bitumen) . .' 9.5 
Mineral aggregate passing f-inch screen, retained on §-inch screen 2. 
Mineral aggregate passing £-inch screen, retained on 44nch screen 11. 
Mineral aggregate passing J-inch screen, retained on £-inch screen 15. 3 
Mineral aggregate passing f-inch screen, retained on 10-mesh sieve 5. 6 
Mineral aggregate passing 10-mesh sieve, retained on 20-mesh sieve 14. 1 
Mineral aggregate passing 20-mesh sieve, retained on 30-mesh sieve 9. 7 
Mineral aggregate passing 30-mesh sieve, retained on 40-mesh sieve 9. 3 
Mineral aggregate passing 40-mesh sieve, retained on 50-mesh sieve. 7. 4 
Mineral aggregate passing 50-mesh sieve, retained on 80-mesh sieve 11. 5 
Mineral aggregate passing 80-mesh sieve, retained on 100-mesh sieve 2. 8 
Mineral aggregate passing 100-mesh sieve, retained on 200-mesh sieve 3. 7 
Mineral aggregate passing 200-mesh sieve 7. 6 
Total 100. 
Table 62. — Analysis of fluxed native asphalt used in bituminous concrete, section 6. 
Specific gravity, 25°/25° C 1.070 
Melting point, °C 55 
Penetration 25° C. 100 grams. 5 seconds 50 
Los3 at 163° C. 5 hours, 20 grams, per cent 2. 51 
Penetration of residue as above. 22 
Per cent of total bitumen insoluble in 86° B naphtha 26. 72 
Fixed carbon, per cent 12. 52 
Soluble in CS 2 (total bitumen), per cent s 94. 85 
Organic matter insoluble in CS 2 , per cent 1. 80 
Inorganic matter insoluble in CS 2 , per cent 3. 35 
Total, per cent 100. 00 
Section No. 7, A and B. — Oil- Asphalt, Penetration Method. 
Section A is much more distinctly mosaic than B and a little 
smoother. It has a few potholes and will probably require a seal 
coat in the spring. The south half of B still retains the mat fairly 
intact, but it appears to be worn very thin. The surface is full of 
short, irregular waves, especially on the north half, where there are 
many bare places and a few potholes. Where cleaned the surface 
shows a somewhat mosaic appearance and toward the north end 
becomes noticeably smooth and regular. 
