Preservation Toolbox

Edited by Helen W. King

If pavement preservation is the right treatment on the right pavement at the right time, what’s the right treatment for your pavements? What’s the right pavement? What’s the right time?

Through the months to come FP2 Inc. will be adding information on the available treatments to aid in your selections for optimal cost-effectiveness and timing for preserving your pavements.

Effective pavement preservation must begin with a pavement inventory, the data of which must be rolled over into a pavement management program that will compare the condition of existing pavements.

This program can be used to establish a preservation regimen that can be applied selectively to improve the pavement condition index (PCI) of the pavements, depending on their age, ridability, traffic volume and loadings.

For flexible (bituminous asphalt) pavements, that regimen might include:

• Crack sealing and patching

• Fog seals (a combination of mixing-type emulsion and approximately 50
percent water, used to seal shoulders and patches)

• Rejuvenation (application of a rejuvenator agent in a procedure similar to fog sealing)

• Sandwich seals (application of asphalt emulsion and a large aggregate,
followed by a second application of asphalt emulsion that is in turn covered with smaller aggregate and compacted)

• Sand seals (application of liquid asphalt or emulsions, covered with fine aggregate or sand, to improve skid resistance, prevent oxidation, and to seal against water infiltration)

• Chip seals (surface treatment in which the pavement is sprayed with asphalt emulsion and then immediately covered with aggregate and rolled)

• Slurry seals (an application of mixing-type asphaltic emulsion, sometimes with additives, mineral aggregate and proportioned water, mixed and spread on clean pavement free of dirt and loose gravel)

• Micro surfacing (polymer modified asphalt emulsion, mineral aggregate, mineral filler, water, and other additives, properly proportioned, mixed, and spread on a pavement)

• Cape seals (application of slurry seal to a newly constructed surface treatment or chip seal), and

• Thin and ultrathin hot-mix asphalt overlays (HMA overlay with one lift of surface course, generally with a thickness of 1.5 in.
or less).

For rigid (portland cement concrete) pavements, preservation techniques include:

• Patching, joint sealing and joint and spall repairs, followed by diamond grooving and grinding to restore ride quality

• Full-depth patching with load transfer retrofit, followed by diamond grooving and grinding, and

• Whitetopping (not unlike a thin HMA overlay, but using a fast-curing, high-durability concrete mix).

Read about these themes in detail via these links:

New! Slurry Seals
Chip Seal
Fog Seal
Diamond Grinding
Micro Surfacing
Repair Priorities