What are the most innovative and effective pavement materials recycling and reuse techniques or technologies?

1 Pavement recycling

Pavement recycling is the process of reusing existing pavement materials to create new or improved pavement layers. It can be done in situ (on site) or off site (in a plant). Pavement recycling can reduce the need for new materials, lower the environmental impact, and save time and money. Some of the common methods of pavement recycling are cold in-place recycling (CIR), hot in-place recycling (HIR), and full-depth reclamation (FDR).

2 Pavement reuse

Pavement reuse is the process of using reclaimed or recycled pavement materials for other purposes, such as base or subbase layers, aggregate, fill, or landscaping. Pavement reuse can also reduce the demand for new materials, conserve natural resources, and minimize waste disposal. Some of the common sources of reclaimed or recycled pavement materials are asphalt shingles, rubber tires, glass, and plastic.

3 CIR technology

CIR is a pavement recycling technique that involves milling the existing asphalt pavement, mixing it with a recycling agent, and placing it back as a new base layer. CIR can be done with or without additives, such as cement, lime, or emulsion. CIR can improve the strength, stability, and fatigue resistance of the pavement, as well as reduce cracking and rutting. CIR is suitable for low to medium traffic roads with mild to moderate distresses.

4 HIR technology

HIR is a pavement recycling technique that involves heating the existing asphalt pavement, scarifying it, adding new asphalt or recycling agent, and compacting it as a new surface layer. HIR can be done as a single pass or a multi pass process, depending on the depth and condition of the pavement. HIR can restore the smoothness, skid resistance, and waterproofing of the pavement, as well as extend its service life. HIR is suitable for medium to high traffic roads with moderate to severe distresses.

5 FDR technology

FDR is a pavement recycling technique that involves pulverizing the existing asphalt and base layers, mixing them with a stabilizing agent, and compacting them as a new base layer. FDR can be done with mechanical or chemical stabilizers, such as cement, lime, fly ash, or emulsion. FDR can increase the bearing capacity, stiffness, and resilience of the pavement, as well as reduce differential settlement and frost heave. FDR is suitable for low to high traffic roads with severe distresses or structural failures.

6 Other technologies

In addition to the previously mentioned techniques, there are other innovative and effective technologies for pavement recycling and reuse. Cold Central Plant Recycling (CCPR) is similar to CIR, but is conducted at a central plant instead of on site. Hot Mix Asphalt (HMA) recycling involves incorporating Reclaimed Asphalt Pavement (RAP) into new HMA mixtures. Warm Mix Asphalt (WMA) recycling refers to the production of HMA mixtures at lower temperatures using additives or foaming agents, and includes RAP in the mixture. Lastly, Recycled Asphalt Shingles (RAS) technology utilizes waste asphalt shingles as a source of asphalt binder or aggregate in HMA or WMA mixtures.