ABSTRACT
Aggregate is the most widely used material in civil and construction engineering, especially in concrete and asphalt mixtures. Aggregate is the main load-carrying agent and fills most of the volume in concrete and asphalt mixtures. Cementitious materials such as cement, lime, or asphalt bind the aggregates together to make a solid mass and help the aggregate carry the load. This chapter discusses all these aspects of aggregates. Worked-out examples are provided where necessary for better understanding. Aggregates are the primary materials in producing Portland cement concrete and asphalt concrete. When the cementitious (binding) material, such as cement or asphalt, binds aggregate together, it forms a solid and stiff mass which can carry external loading. In addition, the aggregate-to-aggregate interlocking can also resist a fair amount of load. Most aggregates are obtained from crushing stones or rocks, and the properties of aggregates are thus inherited from their parent rocks.
