Using Polymer Modified Asphalt Emulsions in Surface Treatments A ...

specifications for asphalt emulsions. Because of the high interest by several entities in
developing improved emulsion test methods and specifications, an ETF of the
Pavement Preservation ETG has been formed by FHWA, with the first meeting held in
April 2008. By cooperating on testing procedures and round robin testing, researchers
from several projects will be more effective in developing standard procedures. Because
funding for the current FLH study ends in September 2008, it is hoped that the ETG
ETF in combination with these other ongoing research efforts will continue to monitor
and update the report-only testing program and eventually recommend pertinent
performance specifications to FLH and to the broader paving industry. It is further
expected that the Guide delivered by this FLH project will be applicable not only to FLH
personnel, but to the industry as a whole.
Other Data Gaps and Future Work
Specific areas identified as currently needing more investigation include:
• Develop performance and specification recommendations for hiking, biking trails;
and parking lots;
• Provide clearer differentiation of material performance given variability in climate
(temperature, humidity) and traffic;
• Update asphalt emulsion test methods in ASTM D-244, including measures for
laboratory and field viscosity and low-temperature residue recovery;
• Develop standard asphalt emulsion residue test methods and specifications that
correlate with performance;
• Develop rheological methods to insure the presence of optimum levels of
polymer modification or gel (high float) formation in the residue;
• Develop aging procedures and polymer/asphalt compatibility or stability tests for
asphalt emulsion residues;
• Improve materials selection, including aggregate specifications and mix-design
procedures;
113