What Is A Full-Depth Reclamation?
What Is A Full-Depth Reclamation?
Full-Depth Reclamation is a method of repairing and stabilizing a roadway by recycling the existing materials.
It involves pulverizing the current surface, mixing in cement and water, compacting, shaping and curing the new stabilized base layer, which can then be topped with a new surface layer.
This process is cost-effective and environmentally friendly as it reduces the need for mining, hauling and disposal of materials.
FDR involves reusing materials from worn-out asphalt pavement to create a new, stabilized base with the addition of cement. This base is then topped with a surface layer of thin bituminous chip seal, hot-mix asphalt, or portland cement concrete.
The recycled base is stronger, more uniform, and more moisture-resistant than the original, leading to a long-lasting, low-maintenance road. Additionally, recycling with cement is cost-effective, with savings of 40-80% compared to removing and replacing the old pavement.
In an era where aggregate supplies are depleted due to urbanization, recycling construction materials through FDR makes economic and strategic sense.
To improve the performance of the system, various materials such as emulsified asphalts, fillers, virgin aggregates or recycled asphalt pavements (RAP) can be added.
The technique is suitable for enhancing the load-bearing capacity of roads that have undergone maintenance procedures, such as pothole patching, seal coats, slurry seals and overlays, as well as handling increased traffic loads.
To create a mix that meets the project’s objectives, it is necessary to examine the existing pavement’s structural soundness, thickness, slope, cross-fall and visual appearance.
Procedure Of Full-Depth Reclamation
The FDR process involves 8 steps as follows:
- Pulverizing existing pavement to a specific depth using a road reclaimer and adding stabilizing materials.
- Adding water to the pulverized material to help achieve the desired density.
- Compacting the material with a sheepsfoot or pneumatic tire roller.
- Grading and adjusting the cross-slope with a grader.
- Kneading and seating any loose aggregates with a pneumatic tire roller or steel wheel vibratory roller.
- Creating a smooth surface by seating remaining loose aggregates with a 12-14 ton static steel wheel roller.
- Applying a fog seal to protect the finished layer, allowing for interim traffic loading.
- Applying a more durable surface treatment or surface course over the new stabilized base course.
Advantages Of Full-Depth Reclamation
Full-depth asphalt reclamation is an effective technique for road repair that offers several benefits, including quicker results, cost-effectiveness, eco-friendliness, suitability for vulnerable areas, and longer lifespan of the repaired road.
Other alternatives may also be used, but full-depth reclamation is a preferred choice due to its advantages. This technique recycles old asphalt to enhance the base of the new asphalt, saving resources and reducing labor costs.
Additionally, it is an eco-friendly option and is ideal for roads built on soft and wet soils, which are prone to wear and tear. With proper execution, full-depth reclamation can result in roads that last for up to 29 years.
