Understanding Asphalt Paving Mix

Understanding Asphalt Paving Mix

How to Choose the Right Asphalt Mix

Go to a shopping center via a road, visit a medical complex, church, school, or your own driveway. Wherever you go, you will see asphalt.

We are not sure if you have ever asked yourself, what is that black stuff? or where does asphalt come from?
A quick explanation is that asphalt is a sustainable and recyclable paving material made from a mix of aggregates, binder, and fillers.

Aggregates are any recyclable materials such as sand, gravel, glass, crushed stone, or other materials. A binder is used like glue to keep all the aggregates and fillers together. The preferred binder material is bitumen – a kind of petroleum made of hydrocarbons. Fillers such as clean sand are used as a filler.

With that in mind, we know that asphalt is a versatile paving material that can be used to pave residential driveways, commercial parking lots, and roads.

However, depending on the application, asphalt can be mixed in several different ways.
Wondering how asphalt paving differs from one project to another?

The secret lies in the method and combination of asphalt mix used to build the pavement. Asphalt mixes may contain different materials in varying proportions depending on the type of project.

Your asphalt engineer may choose any specific aggregate or a combination of several variations. Rocky aggregate materials are available in numerous sizes differing in shapes, volume, and other features.
Apart from the type of aggregate, the mixing method impacts the end result creating all the differences.

Types of Asphalt Mixes (Asphalt Mixing Methods)

Hot Mix Asphalt (HMA)

The process involves heating the bitumen binding material with the aggregate at extremely high temperatures (280°-325°F). The asphalt mix must be laid in hot molten form.

HMA projects largely depend on the outside temperature. Asphalt contractors recommend doing an HMA method when the daytime temperature is 40°F. It ensures the mixes laid at the base remain hot during the procedure.

This mix is suitable for roads with high traffic loads such as highways. HMA structures are strong, repel water, durable, and weather-resistant. This method offers great value to municipalities and cities since it provides low maintenance and easier repairs.

Warm Mix Asphalt (WMA)

WMA is an advanced method compared to HMA, allowing engineers to lay the mixes even in cold temperatures. The technique is ideal for commercial paving, highways, tunnels, interstates, roads, driveways, or parking lots.

The asphalt mix is heated at a lower temperature (200°-250°F). It is also an environment-friendly technology used to lower carbon footprints.

Warm mixes have a lower cost and are more affordable compared to HMA since it uses fewer petroleum-based materials. It is used in more than 30% of projects in the US. It provides the convenience of an easier and faster installation process, lower costs, strength, and longevity.

Cold Mix Asphalt (CMA)

CMA is used for temporary minor fixes. The method involves mixing grounded asphalt aggregate with a combination of hydrocarbon oils. The mixture is prepared at outdoor temperature and laid in cold condition.

This is a cost-effective repair method since no heating is required during the entire process. However, CMA is not as sturdy as the mix formed using the HMA technique.

This mix is ideal for repairing potholes, small cracks, or damaged sections on roads or parking lots. Contractors recommend doing CMA on lesser-used surfaces such as residential driveways or parking lots.

Understanding and selecting the right asphalt mix for your paving project is just as important as selecting the right asphalt paving company for your asphalt paving project.

For more information on the types of materials and mixes of asphalt, visit the Recycled Materials Resource Center.

If you need an experienced asphalt paving company near you, search, our directory for the closest asphalt paving contractor. We list several leading asphalt paving companies in your area. From small repairs to large installation work, you can get a custom quote based on your project type.