FP2 Sponsors Research Evaluating Emulsified Sealer/Binders
For Extending Asphalt Pavement Life

The Foundation for Pavement Preservation (FP2) -- with its public and private sector partners -- is sponsoring new research on the role and applicability of emulsified sealeers, binders and rejuvenators in pavement preservation.

The FP2 Sealer/Binder/Rejuvenator effort also is conducting a series of ongoing local and national workshops, and later, a "lessons learned" workshop. FP2's first national workshop was held in Myrtle Beach, S.C. in March. Local workshops also have been held in Sacramento and Bloomington, Minn.

Typically, highway agencies allow the ride quality and structural condition of pavements to deteriorate substantially before taking steps to preserve their investment. This is costly. An effective pavement preservation program can provide an agency with considerable monetary savings.

The use of emuslified sealers, binders and rejuvenators is of great interest to the pavement preservation community due to their ability to protect oxidized asphalt surfaces, or actually penetrate and rejuvenate them.

The oxidative aging of pavements begins at the time of construction and continues throughout a pavement’s life. However, most oxidative aging occurs within the first two to four years of service life.

This results in the top 0.5-inch or so of the pavement surface becoming more brittle than the underlying material, due to the oxidative actions of water, ultraviolet, and environmental degradation. This can result in raveling and or premature cracking, which often will begin at the pavement surface.

Maintenance personnel in many agencies have combated this aging process by applying spray-applied treatments using distributor trucks. Two major types of spray applied treatments are commonly used: 
o Products that seal the surface
o Products that rejuvenate the surface

Sealers consist of products that are applied to seal pavement surfaces against intrusion of air and water, and to eliminate or minimize raveling of the fine aggregate due to aging of the asphalt binder. These treatments can begin immediately after construction but more typically occur many years later when some form of distress is observed. Sealers have been used in approximately two-thirds of the states.

Rejuvenators are formulated to penetrate into the pavement and then enhance the properties of the asphalt binder of the existing the pavement. These treatments are most commonly used in the western states where ultraviolet exposure appears to promote greater oxidation.

These links will take you to documents related to this research. The S-R Pilot Field Testing Program is a table which gives an idea of the extensive testing each section receives. SR-87 Chip Seal Experimental Design Test diagrams the layout by section for sealers/rejuvenators used in the Winslow, Ariz. pilot project, which is described in more detail in the Winslow Pilot Testing Work Plan.

Lastly, Spray-Applied Sealers/Rejuvenators by State is a large (1.2 megabytes) file containing six maps which indicate state use of different types of applications, and the U.S. climatic regions and states in which this research is taking place.

Adobe Acrobat Reader, commonly downloaded at no charge, is required to view these files.