Fag en A a a OO ag A ee ne 
DUST PREVENTION AND ROAD PRESERVATION, 1914, Al 
Section No. 4 (Buast-FuRNACE SLAG AND REFINED COKE-OVEN TaR). 
The middle third of this section has settled very unevenly. Sand 
and slag chips have lodged in the depressions, from several of which 
the tar has entirely disappeared; in others, the pavement itself is. 
disintegrating. The tar is hard and ‘‘dead,” and the stone and tar 
can be separated under heel pressure. The ridges between the de- 
pressions are cracking. : 
While not as uneven as the middle third, the two end thirds are 
beginning to fail. The surface is so full of irregularities that riding 
over it is uncomfortable. In no place does the surface seem to have 
failed, but the tar is dry and lusterless and can be readily separated 
from the stone. 
Section No. 5 (Biast-FuRNACE SLAG). 
Section No. 5 is still about 14 inches below section No. 4 at their 
junction. The northern two-thirds of this section is on a grade in 
a cut which shows evidence of seepage water. The surface of the 
road is rutted wider and deeper over this part of the section than 
over any other part of the experiments. However, there is no indi- 
cation of failure of the pavement through raveling in the ruts. The 
south one-third of the section has a very satistactory appearance; 
the ruts are not more than one-fourth inch deep, and the surface 
has a smooth, evenly worn, and uniform appearance. 
Section No. 6 (Biast-FurRNAcE S1aa). 
This section is wearing down into wide deep ruts. While in 
general the east rut is more pronounced than the west, there are 
several elongated depressions in the latter which have been swept 
clean of their binder and look as though they would ravel when dry. 
There are also three small spots in the section that seem to be the 
result of settlement rather than wear. The entire surface is mottled 
with large stone about 3 inches in diameter, protruding above the 
general surface. 
Section No. 7 (Buast-FuURNACE SLAG AND OpPEN-HEARTH SLAG). 
Some time during the summer, section No. 7 was swept clean of 
its screenings and dust, apparently in preparation for a surface treat- 
ment. In spite of this, there is no evidence of raveling. The whole 
section shows wide shallow ruts, with the large pieces of slag pro- 
truding. On the fill, from 100 to 200 feet from the south end of 
the section, the west rut is between 2 and 3 inches deep, and the 
depression over the culvert at the north end of the fill is a menace to 
traffic. : 
About 50 feet of the south end of the section was given a surface 
treatment of asphaltic oil during the summer when Price Road was 
treated. The treatment has worn uniformly. 
