What materials are used to produce hot mix asphalt (HMA) pavement?
The components of hot mix asphalt can be simplified into two major components; liquid asphalt cement and aggregates. The liquid asphalt cement (often called asphalt “binder”) is material that coats the aggregate particles and acts as the glue that holds the mix together. The aggregates may consists of natural aggregates (river gravel and sands) or processed aggregates (from quarry and blasting operations). The aggregates provide the structure and framework that gives an asphalt mixture its stability and strength. Another vital component to a well-constructed asphalt pavement is the presence of air voids in the mixture. The amount of air voids in the asphalt is controlled through the aggregate gradation and the quantity of liquid asphalt. The proper blend of asphalt and aggregates is determined prior to construction (during the mix design phase) in order for the mixture to have the desired properties.
