Bases and Subbases for Flexible and Rigid Pavements

The need and use of bases and sub-bases for pavements has been well known for thousands of years. The Romans recognized the benefits of “protecting” the natural earth subgrade from the impact of the repeated loading of their carts and chariots. Roads such as the Appian Way were constructed of multiple layers of stones ( sub-base, base, and surface) and were sloped to drain water away from the road.