ABSTRACT
Flexible/asphalt pavements are generally made up of layers. Each layer is made up of a combination of materials—generally aggregate, binder, and any other additive. The process of designing the optimum combination of materials is called mix design. However, the mix design is conducted in such a way that locally available materials are utilized for economic reasons. Hence, this can be viewed as one of the most important "constraints" in the overall design of an asphalt pavement. Paving asphalt, also known as bitumen, is a product that is mostly obtained from crude petroleum through a series of refining steps. Asphalt can also be used in other forms, such as in emulsified form in asphalt emulsions. The mixing process in the plant involves batching or proportioning a variety of aggregates of different sizes as well as liquid asphalt binder.
