Mixing the asphalt is the real heart of the paving business. Without the proper equipment and know-how, a quality roadway would not be produced.

Asphalt is made of a mixture of different sized aggregates (rock), oil, and other additives (i.e., lime or an oil additive, when these are specified for the job). The additive acts as an anti-stripping agent. Changing the ratio of these ingredients results in different "design mixes." A design mix must be engineered for each particular project to accommodate underlying soil conditions, temperature, moisture content, etc. Once the proper mix is determined, the design is sent to the hot plant operator, who controls the entire operation from the control house (See #1 on the drawing). See below for a numbered sequence of operations, starting at the lower right.

This is a very simplified explanation of a very complex operation. It takes a great deal of knowledge and skill to design the mixes and to guide the hot plant operations to guarantee the perfect mix for the job. The next step is to ride along with the paving crews and watch the final road take form.

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