METHODS OF SAMPLING AXD TESTING HIGHWAY MATERIALS 69 
Table 7. — Volatilization 7o.s-.s- on heating of oil and asphaltic compounds 
Volatiliza- 
Numerical 
True volatiliza- 
tion loss 
correction 
tion loss 
Per cent 
Pa cent 
5.0 
±0.50 
4. 50 to 5. 50 
5. o 
±0.51 
4. 91 to 6.01 
6.0 
±0. 52 
5. 48 to 6. 52 
10.0 
±0.60 
9. 40 to 10. 60 
L5.0 
±0.70 
14.30 to 15.70 
25.0 
±0.90 
24. 10 to 25. 90 
40.0 
±1.20 
38. 80 to 41.20 
Nora. If additional periods of heating are desired, ir is recommended that they be 
made in successive increments of five hours each. 
^%^^p%^^^ 
*— H'(*k) -H 
Pig. 25. — Cleveland open cup 
When the penetration of the sample after heating is required, melt the resi- 
due in the container at the lowest possible temperature and thoroughly mix by 
stirring, taking care to avoid incorporating air bubbles in the mass. Then 
bring it to the standard temperature and test as prescribed under the directions 
for the standard method of test for penetration of bituminous materials (serial 
designation. D 5) of the American Society for Testing Materials {)). (See 
p. 72. > 
When other test* of the sample after heating are required, melt the re-iduc 
in the container at tht lowest possible temperature and thoroughly mix by 
stirring, taking cart to avoid incorporating air bubbles in the mass. 
