Road Base Course:
A
road base is defined as a layer or layers of bound material intended to give
structural integrity to a pavement. The base consists of well-graded material,
usually crushed stone.
Sub-base consists of a lower quality material, sometimes crusher-run product, or the finer fraction of crushed stone production. It can also be a clean, low plasticity fill material. The picture on the left shows placement of sub-base material.
