Function of Road Base and Base Course
Road base is the most important structural layer in bituminous pavement. It is designed to take up the function of distributing the traffic loads so as not to exceed the bearing capacity of subgrade. In addition, it helps to provide sufficient resistance to fatigue under cyclic loads and to offer a higher stiffness for the pavement structure.
However, the base course is normally provided to give a well prepared and even surface for the laying on wearing course. Regarding the load distribution function, it also helps to spread traffic loads to road base but this is not the major function of base course.