EARTH, SAND-CLAY, AND GRAVEL ROADS. 65 
cut is more than 500 feet from the center of gravity of the corresponding fill, 
overhaul will be allowed for the entire amount of material in the cut for the 
actual distance in excess of 500 feet. 
Drainage structures. — [Insert specifications for necessary drainage structures.] 
SPECIFICATION FOR SAND-CLAY ROAD. 
Subgrade. — The graded roadway shall be brought to the elevation, alignment, 
and cross section indicated for subgrade on the plans, and shall be maintained 
free from ruts and other depressions until covered with the surfacing material. 
Natural sand-clap surfacing. — The engineer will designate suitable places for 
obtaining natural sand-clay mixtures for surfacing. 
All unsuitable material that may overlie the acceptable material shall be 
stripped off and removed, and this work will be paid for at the unit-price bid for 
stripping, measured in excavation. 
The natural sand-clay mixture shall then be excavated, hauled to the road, 
and spread. All excavation shall be so conducted that the pits will be left in 
good and sightly condition, and that, where possible, provision will be made for 
draining the pits without additional excavation beyond their limits. 
Hauling.. — The hauling shall be done in wagons of approximately uniform 
capacity, and the loads shall be dumped at such a distance apart as will give 
the amount of material required to construct the surface according to the 
proposed cross section. 
Spreading. — The surfacing material shall be immediately spread on the pre- 
pared subgrade to such depth that the surface, when compacted, will conform 
accurately with the profile, alignment, and cross section, as shown on the 
drawings. All subsequent loads may then be hauled over the surface thus 
formed. 
The construction of the surface shall begin at that point on the road nearest 
the source of material and be continued from such point. In hauling over the 
material as deposited, wagons will be required to use the entire width of sur- 
faced roadway so as to compact the whole section as nearly to a uniform 
density as possible. The teams will not be permitted to follow a single track 
or to form ruts. 
Finishing. — After 500 or 600 feet of roadway have been thus roughly con- 
structed the surface shall be cut up and pulverized to a depth of 2 or 3 inches 
with a plow or harrow and at the same time the shoulders on each side of 
the surfaced portion of the road shall, if necessary, be sufficiently loosened to 
permit of a smooth regular crown being constructed from shoulder to center 
of road. 
When the roadway has been loosened sufficiently, the surface shall be worked 
with a road grader or drag to the true cross section required by the plans. This 
operation shall be repeated daily until the entire surface becomes smooth and 
firm. 
Mixing sand clay. — In case the natural sand-clay mixture, as found, does not 
contain a sufficient percentage of either sand or clay to give a durable surface 
there shall be spread as much of the deficient material as the engineer may 
direct, and this shall be thoroughly mixed and incorporated with the material 
previously spread. In places where a natural mixture is not available suitable 
amounts of clay or sand shall be hauled, spread, and mixed as directed by the 
engineer. 
The process of mixing may require plowing to a depth of 6 or 8 inches and 
harrowing with a disk or tooth harrow, and this work may be required in wet 
weather. 
61531°— Bull. 463—17 5 
