ABSTRACT
This chapter defines the terms used in discussing pavements and how a pavement is designed, constructed and maintained to resist the effects of traffic and water. It lists the nine functional requirements that a pavement must meet. It defines firm ground and discusses the role of the subgrade in the construction and operation of a pavement. The use of topping courses is also described. It notes that a pavement is much more than a road surface as it also provides a road with strength, stiffness and durability. Durability is an important concept as, in any realistic scenario, it is not practical to build and operate a pavement that will last without regular maintenance. It notes that, ideally, pavement managers should be optimising the distribution of the efforts that they devote to the construction and subsequent long-term maintenance of a pavement. This task is complicated by the difficulties associated with predicting future traffic and local climate. While vehicle usage is an obvious influence on pavement performance, it is observed that a commonly under-appreciated fact is that even unused pavements will deteriorate over time. The seven main ways in which water damages a pavement are described, and methods for alleviating each form of damage are outlined.
