Cold mix asphalt is used as a road patch and crack filling material. It offers advantages over hot mix asphalt because it does not require expensive rollers and tampers and can be used year round. Some products are better than others for hot or cold climates and for those climates with varying degrees of moisture and dust. The initial higher cost of quality cold mix asphalt is generally made up through the decreased need for replacement over the years.
The viscosity of a particular cold mix asphalt will affect the thickness and flow of the product at different ambient temperatures. Because the asphalt is not heated before it is applied, this variable can be a major factor in the ease of pouring, spreading and compacting.
Cold mix asphalt is made by mixing an aggregate (often crushed granite or limestone) with an emulsion. Some mixes also include a modifier that allows them to be applied at lower ambient temperatures or to cure slower, helping ensure a long product life. The quality of the aggregate and emulsion, as well as the surface area, and the abrasiveness porosity of each stone affect the overall product.
Environmental and Production Factors
In addition to the ambient temperature, factors such as dust, rain and salt that will frequently come in contact with the cold mix asphalt must be considered when choosing and applying the appropriate product. These same factors should be controlled in the production process to ensure a consistent end product.