Create aggregate by crushing a mixture of sand, rock, gravel, and asphalt cement. The particles are typically crushed down to 4.75 millimeters and above for coarse aggregate, and 4.75 millimeters and below for fine aggregate. You will need to adjust your aggregate based on the climate and traffic needs of the given road. There are a variety of synthetic materials that can be added to aggregates, such as mineral fillers and steel slag. These materials can improve durability over a standard aggregate mix.
Combine the aggregate with liquid asphaltic cement and recycled asphalt into a large sealed rotary dryer drum. The drum will heat the material to remove any moisture, and ensure the aggregate mixes uniformly with the asphaltic cement. Dryer drum mixing temperatures vary based on the mix being processed, but generally range between 300 degrees Celsius and 335 degrees Celsius, and will be regulated by the state's Department of Transportation.
Spread the hot mix onto the ground and then compact it with a heavy roller while still hot. This will create a uniform and level surface. The asphalt is added to the road in a lower layer and a top friction layer. Both layers should be between 4-inches and 8-inches thick.
Spray a final coating of asphalt sealer to provide resistance to drying under direct sunlight, which will cause the asphalt mix to become brittle over time.
