Asphalt Paving is one of the most common methods of paving roadways and parking lots. Asphalt is a black, sticky liquid that can be combined with aggregate to create sturdy, durable pavement for vehicles to drive on. Its durability, low cost, and ease of application make it a popular option for roads, highways, and other paved surfaces. However, there are several factors that should be taken into consideration before deciding on Asphalt Paving or concrete as the material for your project.
Concrete is a gray, solid, and rigid material that can be poured and formed into shape to create sidewalks, driveways, and other paved surfaces. It is a more expensive and time-consuming process to construct than asphalt. Concrete is stronger than asphalt, but it can crack and erode over time due to the freeze-thaw cycle. It also requires a lot of maintenance and repair.
The most commonly used form of asphalt is hot mix asphalt (HMA). It is heated to 300–350 °F and used on high-traffic streets, roads, and interstates. Other specialty asphalt mixes include stone-matrix asphalt, which helps ensure a strong wearing surface, and porous asphalt pavements that allow water to pass through the road for stormwater management.
In order to achieve a desired HMA performance, it is important to have the proper mixture of ingredients. Asphalt binders are manufactured from the byproducts of crude oil, and the composition of these binders can vary. For this reason, it is important to monitor the composition of the binders and keep them consistent.
Another factor that impacts the HMA performance is the amount of recycled aggregate material in the mix. The use of recycled asphalt reclaimed from road construction sites reduces the overall cost of the HMA and provides environmental benefits. However, the TFHRC recommends using recycled asphalt only when it has been thoroughly tested and meets HMA performance requirements.
The final consideration in the choice of a pavement material is its constructability. Constructability refers to the ability of a pavement design to facilitate construction, traffic control and access for construction crews. Asphalt pavements are the most constructible paving materials, which contribute to their rapid construction and popularity in design-build contracting.
As with all paving materials, asphalt has advantages and disadvantages. One advantage is its flexibility, which makes it easy to apply and shape to meet the needs of a particular paving project. Its ability to conform to curves and other irregularities is also a benefit. Additionally, the dark color of asphalt can help to melt snow and ice, making it safer for drivers. Another downside to asphalt is its dependency on petroleum, which can cause environmental concerns. However, the long lifespan of asphalt – which can be reused or recycled – offsets this. It also uses less energy to produce than concrete. For these reasons, a majority of roads and streets around the world are paved with asphalt. The United States alone has over 2.2 million miles of asphalt roadways, and over 96% of primary and Interstate roads are paved with this material.