Asphalt is a highly-beneficial paving material that can be used in various applications within the construction industry. There are several types of asphalt mixes, including hot mix asphalt (HMA), warm mix asphalt (WMA), cold mix asphalt, cut-back asphalt concrete, mastic asphalt concrete, and variations of them all. By customizing aggregate material composition, binders, and more, contractors can achieve the proper asphalt pavement mix needed for the job. In this blog, we will discuss the principle differences between the two most popular forms of asphalt: HMA and WMA. Continue reading to learn more about hot mix asphalt and warm mix asphalt, and what makes them so different.
Hot Mix Asphalt
Hot mix asphalt is just that: hot. It is poured at a high temperature of 300 to 350 degrees Fahrenheit, and is only applied when outdoor temperatures exceed 40 degrees Fahrenheit because it cools so rapidly. In the United States, it is the most common method of asphalt paving used for high-traffic pavements like highways, roads, interstates, and more. This is largely due to its advantageous qualities. Hot mix asphalt is water and weather resistant, flexible, and environmentally-friendly. Interesting uses for HMA includes environmental liners for places like reservoirs, landfills, and fish hatchery ponds.
Warm Mix Asphalt
Warm mix asphalt is manufactured and shipped at lower temperatures, usually between 200 and 250 degrees Fahrenheit, and it has a slower cooling rate than HMA. This means it can be used in colder seasons or climates for road, highway, and interstate construction. For the same reason, it can be shipped long distances as well. WMA is used in roughly 30 percent of paving projects around the country because of its slow cooling rate, versatility, environmental benefits, and health benefits for workers. Since WMA is poured at lower temperatures, it reduces the amount of dust, smoke, and fumes created when applying HMA. This is safer for workers as well as the surrounding environment. It is also a wise choice for paving in tunnels, especially on a poor air quality day!