Recycling Methods for Sustainable Pavement Rehabilitation

As we work to preserve resources and reduce waste, “smarter” methods have been increasingly popular, such as using new recycling techniques when it comes to roadways. When implementing these recycling techniques, there are cost savings up to 50% compared to the previous method of removing and replacing the pavement altogether. There are three popular techniques that employ recycled materials: Cold-in-Place Recycling (CIR), Cold Central Plant Recycling (CCPR), and Full Depth

Reclamation. All of these save money and have a positive impact on the environment! 


Cold-in-Place Recycling 

Cold-in-Place Recycling is the process of using a train of equipment to refurbish old and distressed pavement. This transformation begins when the distressed pavement is milled, screened, and crushed, breaking the old pavement apart and creating a new aggregate gradation as the base ingredient of the cold-in-place recycled product. From here, the recycled pavement is mixed with an engineered emulsion, a recycling agent, or with a foamed asphalt, and additional aggregates if needed.  The final cold-mixed asphalt material is repaved and compacted. After a period of curing, the surface is then finished with a wearing course treatment and is set for new traffic! Using the Cold-in-Place Recycling method, construction time, project traffic, and the carbon footprint are all significantly reduced.


Cold Central Plant Recycling

Cold Central Plant Recycling is very similar to the Cold-In-Place Recycling with a few exceptions.  As stated in the name of the process, this is performed off the job site at a central plant location.  There can be recycled asphalt from multiple locations and sources rather than a single source.  It is necessary to properly stockpile and characterize the different recycled asphalt pavement before it can be used.  Some projects allow for blending of the different recycled asphalt pavements – in these situations, it is critical that the blending process creates a consistent and homogenous product before being treated with engineered emulsions, recycling agents, or foamed asphalts to make the final product.  The recycled asphalt is then mixed with an agent and is shipped to the project site to be paved, compacted, and a surface treatment applied after a curing period. Implementing recycled asphalt from old roads saves time, money, and allows the agency to recycle their previous materials for this new roadway. 


Full Depth Reclamation

In Full Depth Reclamation, the existing asphalt is pulverized or milled through the full section of asphalt and then mixed with the underlying base as well as a stabilizing ingredient to create a homogenized layer. Stabilization can be achieved through a few different approaches, mechanically, chemically, asphalt stabilized, or a combination of treatments.  Mechanical stabilization can be accomplished by adding crushed aggregates, RAP, or crushed PCC.  This improves the strength of the layer by increasing the aggregate particle interlock.  Chemical stabilization uses products like lime, cement, or lime/fly ash to form a binder.  Asphalt stabilization is the process of using engineered emulsions, recycling agents, or foamed asphalt. From here the recycled asphalt is then compacted to provide a new stabilized base. This method allows for older and failed asphalt to be recycled and form a new and stronger subgrade to build the roadway. 


Sustainable Pavement Rehabilitation With G3 Quality 

We are firm believers in reducing waste and giving old materials a new use when it comes to roadways and pavement. Implementing these recycling methods is not only cost-effective, it also reduces waste, the carbon footprint, and inconvenience for commuters. Let us help you create the best plan for your next pavement project!

At G3 Quality, we are industry leaders who are always embracing change and excellence. We are an elite team of engineers and professionals who provide world-class quality management, pavement engineering, materials design, construction inspection, and testing on infrastructure projects throughout California and the Western United States.

To learn more about how G3 Quality can contribute knowledge, expertise, consulting, and professional services to your project, contact us.