Chip Seal – Stone & Sand
Chip seals combine an asphalt layer and cover aggregate to provide a skid resistant wearing surface. The asphalt renews aging surfaces, fills micro-cracks, and seals and waterproofs the pavement. It binds the aggregate, which protects the asphalt and provides durable friction. For stone seals, we prefer high quality, clean, hard, cubical and uniformly-sized aggregates. Sand seals need fine, granular, hard and durable sand that is free of organic matter. The asphalt is applied as a water-based emulsion, which bonds to the underlying pavement and the cover aggregate as it cures. Latex may be added to the emulsion before application for durability. Generally, these seals last from three to seven years, depending upon the types of materials, traffic and, most importantly, the condition of the pavement before construction.
Benefits of Stone and Sand Seals
- Waterproofs and seals small cracks and imperfections
- Enriches aging, oxidized asphalt
- Improves skid resistance and surface macro texture
- Protects underlying pavement from traffic wear
- Protects the environment and worker safety with non-polluting, water-based emulsion
- Stretches maintenance dollars as one of the lowest cost treatments available
- Effective preventive maintenance preserves the value of your pavements
The Sealing Process
All States Materials Group emulsions are formulated to be compatible with the project aggregate and to break quickly for early chip retention. We use aggregates that have been tested for proper gradation and cleanliness. A laboratory design with the project materials determines the correct asphalt emulsion and aggregate application rates. There should be enough asphalt to give the proper embedment (and therefore bonding) of the aggregate in the asphalt, and just enough aggregate to cover the surface. After any repairs are made and the pavement is cleaned of any loose debris, a properly adjusted and calibrated distributor truck sprays the emulsion on the pavement at the predetermined shot rate. This is immediately covered by the aggregate applied by a continuous, self-propelled aggregate spreader. The seal is then rolled to properly orient and seat the aggregate. Once the seal is cured, it is swept of any excess aggregate and traffic is returned to normal speed. Prior to curing, traffic should be strictly controlled to avoid vehicle damage from loose aggregates.
Where and When to Use Stone and Sand Seals
Chip seals are suitable for all roads from rural to high traffic volume highways. Stone seals give the best, most durable friction, and sand seals can fill small cracks and voids. Chip seals may also be used on low-traffic, well-graded gravel roads as a first asphalted surface. For preventive maintenance, the pavement to be sealed should be essentially sound and properly drained. It should have a good profile and alignment with only minor asphalt aging and cracking. There should be no sign of sub-base movements or surface bleeding. When warranted, potholes and cracks should be filled. The surface should be swept of any stones, sand, mud or other loose debris. Chip seals are the ideal treatment for aging, good quality pavements you want to preserve.
All States Materials Group wants to make sure your sealing job is a success. We can help with determining the right treatment at the right time for your pavement. For your overall road program, we can help you evaluate gravel road upgrade alternatives, single versus multiple surface treatments, and equipment rentals and aggregate supply instead of our complete turnkey contracting. Contact our professionals for more information about stone and sand sealing.