2
Life Cycle Assessment
DECLARED UNIT
The declared unit is 1 short ton of an asphalt mixture
(UNSPSC Code 30111509: Asphalt Based Concrete) as defined
as “a plant-produced composite material of aggregates,
asphalt binder, and other materials.”3
LIFE CYCLE PHASES
This EPD covers the raw material supply, transport, and
production life cycle phases (A1-A3). It does not include
construction (placement and compaction), use, maintenance,
rehabilitation, or the end-of-life life cycle phases (phases A4, A5,
B1-7, and C1-4).4
Materials (A1):
This stage includes raw material extraction,
refining, and energy production.
Transport (A2):
This stage includes transport of raw materials to
the asphalt plant.
Production (A3):
This stage comprises all plant operations
involved in the production of asphalt mixtures. Data for this
stage is plant-specific.
LIFE CYCLE INVENTORY
This EPD was created using plant-specific data for asphalt mix
production of the manufacturing life cycle phase. Potential
variations due to asphalt mixture design, supplier locations,
manufacturing processes, efficiencies, and fuel use are
accounted for in this EPD. All other upstream data sources were
prescribed and are publicly available and freely accessible to
ensure transparency and comparability. Use of the prescribed
data sources ensures comparability among the EPDs developed
by limiting any variability due to differences in the upstream
data within the system boundaries.5
Environmental Impacts
The life cycle impact assessment results are relative expressions
and do not predict actual impacts on category endpoints,
the exceeding of thresholds, safety margins, or risks.
INTERPRETATION
The information presented in this EPD can be used to model
the environmental impacts of asphalt mixtures purposed to be
part of (but not limited to) roadway, parking lot or recreational
pavements. This EPD alone does not provide the environmental
impacts of the entire pavement structure itself and does not
make any statements that the product covered by the EPD is
better or worse than any other product.
Comparison of the environmental performance of asphalt
mixtures using EPD information shall be based on the product’s
performance and function, and therefore EPDs shall not be
used for comparability purposes when the asphalt mixture
performance and functions are not the same.
NAPA verified
asphalt mixture EPDs that are expected to meet the same
performance and function can be compared.
EPDs of other
programs may not be comparable because they could be
calculated using a different PCR.
ADDITIONAL ENVIRONMENTAL INFORMATION
None
DECLARATION OF LIMITATIONS
This EPD reports the results of a cradle-to-gate LCA for asphalt
mixtures. This EPD may be used as a data input for full life cycle
assessments to compare the environmental impacts of different
asphalt roadway, parking lot, or recreational pavement design
alternatives.
DATA GAPS
- This mix uses a modified asphalt binder. The upstream impacts associated with the process of extraction, manufacturing/production, and transportation of the materials used in the modification process have not been accounted for in this EPD.
- The impact of recycling asphalt shingles was estimated using data for processing reclaimed asphalt pavement. The source of the shingles (tear off or manufacturing waste) is not being accounted for.
An Environmental Product Declaration for Asphalt Mixtures