What is asphalt? Asphalt, also called Blacktop, is a engineered mixture of approximately 95% aggregate, which could be stone, sand, or gravel, and 5% liquid asphalt cement as a binder.
The mixture is heated to about 300 degrees in order to bind the components together and to make it possible to transport and apply the material.
There are several different grades of asphalt that can be used dependant on the specific application.
Base applications contain larger stones for a stronger base, while overlay applications contain smaller gravel and a higher percentage of sand in order to produce a smoother surface.
How is asphalt applied? While the mixture is still hot, it is delivered to the project and paved on top of a base or subgrade that has already been prepared. The depth and strength of the base is an important factor to the longevity of the asphalt and can be gravel, chip seal, or existing asphalt.
Preparation of the base is necessary to ensure a solid bond between the base and the asphalt. Preparation may include the use of brooming machine to remove debris, milling of the existing surface, use of weed-killer, or the application of a tack coat from a distributor truck to helps glue the new pavement to the existing surface.
Once the surface has been prepared the new asphalt can be applied. A dump truck containing the paving material from the plant backs into the paver and dumps the material into the hopper. The paver then lays a smooth layer at a predetermined thickness. The material is then compacted using vibratory or static steel wheel rollers.
Very soon after paving, the mixture cools and hardens and can be re-opened to traffic.
How long does asphalt last? The life cycle of asphalt can vary based on several factors such as climate, traffic, base, and maintenance. As a rule of thumb, using industry standard practices, good design, proper maintenance and a solid base should provide 15-20 years of useful life.
How is asphalt maintained? A asphalt emulsion sealer should be applied every 2-5 years depending on your specific location. This sealer waterproofs your asphalt and fills tiny cracks formed by hardening of the asphalt and traffic. Keeping water out of the asphalt will minimize the effects of freezing and thawing that expand and contract your pavement. Any cracks or potholes should be filled prior to applying the sealcoat.
How much does asphalt cost? There are many variables to the cost of an asphalt project, such as size, location, depth, and existing base.
Wm. Light Paving Company will be happy to review your specific project and provide a quote tailored to you.
