Milling & Pulverizing
Since 1984, Walbec has pioneered the road-building reclamation processes by recycling existing asphalt pavements via CAT 1000 cold planers. Today, we have one of the country's largest fleets of reclamation equipment as our team continues to evolve the road reclamation process with local agencies, OSHA, and equipment manufacturers. Our specialties include high-production pavement removal and roadway milling to stringent ride profile specifications and soil stabilization.
During milling and pulverization, our crews adhere to stringent safety protocols. Walbec is a leader in the Silica/Asphalt Milling Machine Partnership, a study of exposure to respirable crystalline silica. As participants in the first study on silica dust during milling machine use, the team outlined best practices to operate and work around equipment while minimizing exposure to unhealthy silica dust. Mitigating exposure to our team members continues to be a top priority.
Today, asphalt milling machines include vacuum systems that create a negative pressure to remove a mix of dust particles and water vapor inside the drum housing. This mixture is then deposited onto the mill conveyor, improving the air quality for those operating the equipment.
The milling process involves using Walbec's versatile reclamation equipment to remove two to 12 feet of pavement widths and depths up to 12 inches in a single pass. Customers benefit from the maximum output and high daily production rates from variable speed drums, advanced leveling systems, and superior digital displays.
Pavement pulverization and soil stabilization are also options. High-production pulverizers cut up pavement up to a width of 8 feet and a depth of 16 inches deep. Unlike milling, pulverizing, also known as full-depth reclamation, involves grinding the entire thickness of the existing asphalt pavement, along with the base and subbase, and breaking down the existing pavement into granular materials. This material creates a foundation for new pavement layers. Pulverizing is often used when the pavement is severely deteriorated or requires substantial structural improvements.
The milling and pulverizing processes are crucial in asphalt pavement construction and serve several essential purposes, contributing to the road infrastructure's overall quality, safety, and longevity. Benefits include:
- Smooth Surface Preparation Leading to Improved Ride Quality: Over time, road surfaces can become uneven, cracked, rutted, or deteriorated due to heavy traffic, weather, and wear and tear. Milling removes these imperfections, creating a smooth and uniform surface for the new pavement. Milling helps to eliminate bumps, potholes, and other surface irregularities, offering an enjoyable driving experience.
- Enhanced Traction and Safety: Removing worn and slippery surface material improves traction, reducing accidents during wet or icy conditions.
- Preservation of Drainage: Milling can help restore proper pavement drainage by eliminating surface depressions and irregularities leading to water pooling or improper runoff. Proper drainage prevents water-related damage and prolongs the lifespan of the pavement.
- Optimal Pavement Bonding: Milling roughens the surface of the existing pavement, creating a textured surface that allows the new asphalt layer to bond more effectively. This bonding is critical for the longevity and durability of the new pavement.
- Cost-Efficiency: Throughout the milling process, only the deteriorated surface layer of the pavement is removed, preserving the underlying layers that are still in good condition. This can result in significant cost savings compared to a complete pavement reconstruction.
- Environmental Benefits: As the most recycled product in the U.S., asphalt millings are recycled and used to produce new asphalt material, reducing the need to dispose of large quantities of old pavement materials in landfills.
- Time Savings: Milling is generally faster than traditional road reconstruction methods. With efficient removal of the old surface layer, road construction projects can be completed quicker, minimizing disruption to traffic and reducing the overall project timeline.
- Preparation for Overlays: Proper surface preparation through milling ensures a stable and consistent overlay base. This prevents issues like cracking and uneven settling in the new pavement when adding a new layer of asphalt or other materials to an existing road.
- Customization of Pavement Profile: The milling process allows for precise control over the depth of the pavement removal, ensuring specific road profiles and grades are met for each project. Walbec mills have high-precision leveling systems to control the milling machine's cutting depth, slope, and speed to achieve smooth ride pavements. The leveling systems consist of controllers, read-out panels, sonic sensors, and contact sensors to set, control, and monitor milling depths and slope parameters throughout the milling process.
The quality of the finished milled surface is not only a product of the machine operation, but the stability of the teeth used to cut into the existing pavements. Milling operators perform multiple inspections of the cutting teeth throughout each shift and frequently replace worn teeth to ensure the highest quality.