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

Numerous decision tools and best practices have been developed by state highway
agencies and industry trade organizations for matching the type and degree of
pavement distress with the appropriate form of surface treatment. Hicks et al (2000)
provide a review of some of the best known of these practices, and present a framework
which can be used to determine the most cost-effective treatment alternative (79). This
section of the report focuses on those treatments which are regularly employed using
PME including chip, slurry, and cape seals; and microsurfacing.
One of the simplest and best known approaches to determining cost-effectiveness is the
Equivalent Annual Cost method or EAC. EAC is determined as follows:
EAC = (unit cost of treatment) / (expected life of treatment in years).
Table 11 presents examples of the EAC cost-effectiveness of various treatment types.
Table 11: Examples of EAC Cost-Effectiveness
Treatment
Approx. Average
Avg. Longevity (years) EAC
Cost per s.y. (1) < 100 ADT 100 – 500 ADT
(100-500 ADT)
Chip Seal $1.30 8 5 $0.26
Chip Seal
Modified
$1.69 -- 6.5 (2) $0.26
Slurry Seal $1.08 7 5 $0.22
Slurry Seal
Modified
$1.40 -- 6.5 (2) $0.22
Cape Seal $2.08 11 7 $0.30
Cape Seal
Modified
$2.70 -- 9 (2) $0.30
Microsurfacing $1.40 11 6 $0.23
(1) Costs may vary widely depending on materials used, location, etc.
(2) Number of years of longevity needed to achieve EAC break-even point assuming average
cost increase of 30% for PMA emulsions.
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