FDR is the rehabilitation technique in which the full thickness of the asphalt pavement and a predetermined portion of the underlying materials (base, subbase and/or subgrade) is uniformly pulverized and blended to provide an upgraded, homogenous base material. Treatment depths vary depending on the thickness of the existing pavement structure, but generally range between 4 to 12 inches (100 and 300 mm).

FDR consists of pulverization/reclamation of the existing materials, adding more materials (when necessary), mixing, initial shaping of the resultant mix, compaction, final shaping or "tight blading," and application of a bituminous surface or wearing course.

Reclamation of the existing asphalt bound layers with the underlying materials produces a "granular" pavement layer which can be used as is, can have additional granular materials placed over it, or can be enhanced with the addition of an additive or "stabilizing additive." The addition of a stabilizing additive is usually required if the reclaimed material does not, by itself, have the necessary mechanical properties and/or structural strength to support the anticipated loads.

A broad range of stabilizing additives, in either a dry or liquid form, can be used including calcium chloride, magnesium chloride, lime (hydrated or quicklime), fly ash (type C or F), cement kiln dust (CKD) or lime kiln dust (LKD), Portland cement (dry or slurry), asphalt emulsion (normal, high-float, polymer), foamed/expanded asphalt or combinations of two or more of these additives. If the existing materials will not provide the desired gradation, material properties or depth required, additional granular or other materials can be added to the roadway prior to or during the FDR process.

 FDR advantages include:

• Conservation of non-renewable resources
• Energy conservation compared to other reconstruction methods
• Few pieces of equipment are required
• Elimination of bumps and dips, rutting, potholes, patches, and cracks
• Subgrade deficiencies can be corrected by stabilization
• Problems with existing aggregate gradation can be corrected with proper selection of new granular materials
• Deteriorated base can be reshaped to restore surface profile and drainage
• Significant structural improvement with the addition of stabilizing additive(s)
• Produces thick, bound layers that are homogeneous
• Permits more flexibility in the choice(s) of wearing surface type and thickness
• In-place construction and high production rates improve safety by reducing traffic disruptions and user inconvenience
• Economic savings are realized

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