SAMPLING AND TESTING HIGHWAY MATERIALS. 
9 
the side of the cylinder 6 inches from the bottom . The spout is inclined at an angle 
of 2° with the horizontal and is 2h inches long. A notch is filed across its lower end, 
as shown, to stop the drip from the displaced water. To determine the specific 
gravity, the dried and cooled sample shall he weighed to the nearest 0.5 gram and 
immersed in water for 24 hours. The pieces shall then be surface-dried individually 
with a towel, the sample reweighed and immediately placed in the cylinder, which 
has been previously filled to overflowing with water at room temperature. 
(2) The weight of water displaced by the sample shall be used to calculate its 
apparent specific gravity. The difference between the original weight of the sample 
and its weight after 24 hours shall be used to determine the absorption. 
Zl Galvanized 
Iron ^ r r5"D. 
Note: Notch is filed across 
lower end of spout +/g|" (2°) 
to prevent drip.z=. ] 
\Three lugs soldered on) 
bottom symmetrically. 
Fig. 7. — Vessel used in making specific-gravity and absorption tests. 
6. TESTS FOR APPARENT SPECIFIC GRAVITY OF SAND, STONE, OR 
SLAG SCREENINGS AND OTHER FINE NON-BITUMINOUS HIGHWAY 
MATERIALS. 
(A. S. T. M. Standard Methods, Serial Designation: D 55-19.) 
(1) The following tests, "Le Chatelier" and "Jackson," are equally suited for use 
in determining the apparent specific gravity of sand, stone, and slag screenings and 
other fine non-bituminous highway materials and may be considered as alternates. 
I. LE CHATELIER TEST. 
(2) The determination of specific gravity shall be made with a standardized Le 
Chatelier apparatus which conforms to the requirements illustrated in figure 8. This 
apparatus is standardized by the United States Bureau of Standards. Kerosene free 
from water, or benzine not lighter than 62° Baume, shall be used in making this 
determination. 
