The Future of Road-making in AmericaHulbert, Archer Butler
History
The Future of Road-making in America
Hulbert, Archer Butler
Roads; Roads -- United States; Roads -- United States -- Design and construction
The roadbed should be first graded, then carefully surface-drained. The
earth should then be excavated to the depth to which material is to be
spread on and the foundation properly shaped and sloped each way from
the center so as to discharge any water which may percolate through.
This curvature should conform to the curvature of the finished road. A
shouldering of firm earth or gravel should be left or made on each side
to hold the material in place, and should extend to the gutters at the
same curvature as the finished road. The foundation should then be
rolled until hard and smooth.
Upon this bed spread a layer of five or six inches of broken stone,
which stone should be free from any earthy mixture. This layer should be
thoroughly rolled until compact and firm. Stone may be hauled from the
stone-crusher bins or from the stone piles in ordinary wheelbarrows or
from wagons, and should be distributed broadcast over the surface with
shovels, and all inequalities leveled up by the use of rakes. If this
method of spreading is employed, grade stakes should be used so as to
insure a uniformity of thickness. After the stakes are driven the height
of the layer is marked on their sides, and if thought necessary a piece
of stout cord is stretched from stake to stake, showing the exact height
to which the layer should be spread. Spreading carts have been recently
invented which not only place the stone where it is needed without the
use of shovels, but spread it on in layers of any desired thickness and
at the same time several inches wider than the carts themselves.
If the stones have been separated into two or three different sizes, the
largest size should compose the bottom layer, the next size the second
layer, etc. The surface of each course or layer should be thoroughly and
repeatedly rolled and sprinkled until it becomes firm, compact, and
smooth. The first layer, however, should not be sprinkled, as the water
is liable to soften the foundation. The rolling ought to be done along
the side lines first, gradually working toward the center as the job is
being completed. In rolling the last course it is well to begin by
rolling first the shoulderings or the side roads if such exist.
A coat of three-quarter inch stone and screenings, of sufficient
thickness to make a smooth and uniform surface, should compose the last
course, and, like the other layers, should be rolled until perfectly
firm and smooth. As a final test of perfection, a small stone placed on
the surface will be crushed before being driven into the material.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account