Table of Contents

2.6.1 General

The primary division between mix types is in terms of particle size distribution (generally referred to as grading). Within each grading type, there are variations in terms of binder type as well as types and proportions of component materials for particular applications. Further variations to asphalt mix types include mixes for specific application such as ultra-thin surfacing or warm mix asphalt.

The principal mix types based on particle size distribution are:

  • dense graded asphalt (DGA), also called asphaltic concrete (AC)
  • stone mastic asphalt (SMA)
  • open graded asphalt (OGA), also called open graded porous asphalt (OGPA) and open graded friction course (OGFC)
  • fine gap graded asphalt (FGGA).

Figure 2.1 indicates typical particle size distributions for the principal mix types. An indication of the relative proportion of components is shown in Figure 2.2.

Figure 2.1: Typical particle size distributions for various mix types

Figure 2.2: Typical mix components by volume