Often times people think that asphalt is simply asphalt, but in actuality it is a lot more than that. It is a mixture of bitumen and crushed rock, which is used to seal a road or driveway. Using asphalt can help prevent potholes and cracks in a road. The type of asphalt used is also important and can be categorized into two different types: open-graded asphalt and asphalt cement. Here is what you should know before hiring asphalt contractors:
Bitumen
Typically, bitumen is used as an adhesive and waterproofing material. It is a polycyclic hydrocarbon made up of 87 percent carbon and 2 percent oxygen. It is obtained through the distillation of crude petroleum. Bitumen is typically mixed with sand or a well-graded aggregate, and the percentage of bitumen is usually between three and ten percent. The mixture is then heated and sprayed on the road material. The process is repeated several times, and bitumen is refined several times, until it is the desired grade.
Crushed Rock
Using crushed rock is a common technique in road construction. There are different types of crushed rock, and each has different properties that can affect the strength of a road. It can be used for many purposes including a base for a driveway, walkway or decorative landscaping project. The material can be recycled and is much less expensive than using natural stones. The recycled material is also more versatile. It can be used for roads, driveways, parking lots, landscaping projects, drainage systems and septic systems.
Asphalt Cement
The physical properties of asphalt cement, such as viscosity and penetration, are used to determine the consistency of the material. The absolute viscosity test utilizes a partial vacuum to induce flow in a viscometer. The amount of absorption of the aggregate also affects the performance of hot mix asphalt. This refers to the void spaces in the particles that are filled with the asphalt binder. A sufficient number of voids prevents bleeding and allows for a slight additional amount of compaction under traffic.
Open-Graded Asphalt Technology
Using a mix designed for a specific application will ensure that the product has the required properties for the function. This includes the ability to flexibly absorb deformations, workability, resistance to moisture damage, and a retention coating to prevent stripping. The basic steps of the mix design procedure are determining the aggregate content, mixing temperature, and moisture damage susceptibility. During the mix design phase, it is important to ensure that all additives required for the mix are included.
