Page 398 - Moving the Earth_ The Workbook of Excavation
P. 398
ROADWAYS
8.60 THE WORK
FIGURE 8.46 Windrow processing sequence. (Courtesy of Portland Cement Association.)
ally tire prints, close to final grade. They are found chiefly in heavy soils. Material bladed onto
them may not form a good bond, so that loosening and spalling will occur in the finished pavement.
Compaction planes are eliminated or made harmless by scratching the surface with a spike-
tooth harrow, weeder, or steel broom pulled by a small tractor. Final grading may then be done in
a conventional manner, except that the surface must be kept damp during the work.
If compaction planes are at or very close to final grade, or if the surface is partly set, it may be
economical to waste any cuttings at the side, rather than to try to use them in the road.
