ABSTRACT
The performance of the pavement system as a whole depends greatly on the construction of the supporting subgrade, subbase, and base (if any) layers. There is a saying in building construction that “there is nothing more expensive than a cheap foundation.” This is also true of pavements. Quality construction of these layers ensures a well-drained, uniformly supported pavement, and makes it much easier to build a smooth pavement because the paver has a smooth working platform. In contrast, a weak subgrade generally requires time-consuming and costly full-depth reconstruction to correct.
