Embedded Files
There are a variety of resources that exist online to assist producers with understanding EPDs, and help them develop EPDs.
Understanding epd Development
Understanding epd Development
Expressing Sustainability in terms of Strength:
Product category rule (pcr)
Product category rule (pcr)
The standard test method that everyone uses to perform a test. It is:
developed using a consensus-based approach that has a variety of industry representatives
ensures the test is performed the same across multiple facilities and operators
ensures comparability between test results
Life cycle assessment (LCA)
Life cycle assessment (LCA)
Performing the test following the standard test method. The LCA should incorporate the life cycle stages and modules allowed by the PCR. For cement and concrete, the PCR allows inclusion of:
A1 (required): materials extraction and constituent production
A2 (required): transportation of constituent materials to the product production facility
A3 (required): product production
A4 (optional): transportation of the product to the use location
A5 (optional): installation
Environmental Product declaration (EPD)
Environmental Product declaration (EPD)
The result of the test that was performed following the standard test method.
The result goes through a third-party verification process to check that the standard test method was followed appropriately.
This may include a gut check that the resulting values make sense.
Further information may be requested by the verifier to perform the verification.
FHWA resources
FHWA resources
FHWA has documents explaining what EPDs are, the fundamentals of EPDs and PCRs, a fact sheet for sustainable project delivery, videos and webinars, and Community of Knowledge recordings.
Federal LCA Commons
Federal LCA Commons
FHWA Pavement Life Cycle Assessment
Asphalt and concrete LCI
Provides information on:
how to gather data
how to use your data with openLCA
OpenLCA Tutorials
OpenLCA Tutorials
Visit this webpage for easy OpenLCA tutorials and case studies completed in OpenLCA in other domains that may be helpful.
What kind of data do I need for an Epd?
What kind of data do I need for an Epd?
Mixture proportions / Constituent quantities
Transportation distances of the constituents to the concrete production facility
Energy needs for concrete production
Developing epds
Developing epds
There are free, online tools that can provide initial indications (NOT EPDs) of the embodied carbon emissions associated with a concrete mixture. The results of these estimations are not verified and are NOT EPDs. However, you can use these to get you started.
NRMCA's Concrete Carbon Calculator
NRMCA's Concrete Carbon Calculator
FHWA's LCAPave
FHWA's LCAPave
https://www.fhwa.dot.gov/pavement/lcatool/
The LCAPave tool uses the data and processes in OpenLCA, such that LCAPave and OpenLCA should provide the same results if used correctly.
The following links will connect you with places to get ISO-conformant EPDs:
Theta and GCCA Tool
Theta and GCCA Tool
The Theta and Climate Earth developers of ISO-conformant, verified EPDs have been verified to estimate GWP of construction materials products within 2% of each other.
How do the estimating tool results compare with the iso-conformant epd?
How do the estimating tool results compare with the iso-conformant epd?
The NRMCA Concrete Carbon Calculator tool allows the user to provide concrete mixture proportions, and likely uses industry-average data for transportation, constituent productions, and concrete production.
The OpenLCA tool allows the user to input concrete mixture proportions, mixture-specific transportation data, as well as fuel and energy data for productions.
Estimates from Openlca vs NRMCA Concrete Carbon Calculator tool
Estimates from Openlca vs NRMCA Concrete Carbon Calculator tool
The GWPs for 14 concrete mix designs are compared against the 1:1 line demonstrating equivalent GWPs between the two tools. The NRMCA tool appears to overestimate the GWPs compared to the OpenLCA tool.
Verified EPDs have not yet been received for these 14 mixture designs, so no comparison is made to the verified EPD GWP.
Note that the LCA Pave tool is based on the OpenLCA inputs and therefore Open LCA and LCA Pave should yield the same result.
Verified EPD GWPs vs. OpenLCA vs. NRMCA Concrete Carbon Calculator
Verified EPD GWPs vs. OpenLCA vs. NRMCA Concrete Carbon Calculator
Two concrete mixtures have ISO-conformant, verified EPDs with GWP estimates. The ISO-conformant, verified EPDs were developed by Climate Earth. Both EPDs used supplier specific primary data for the cement contributions to the concretes' GWPs.
The GWPs estimated from the OpenLCA and NRMCA tools are compared in the figure on the right against the 1:1 line which indicates equivalency. Once again, the NRMCA appears to estimate a higher GWP than the OpenLCA tool.
For the concrete mixture represented by the triangular marker, the OpenLCA estimated GWP 16.9% lower than the verified EPD projected. The NRMCA tool estimated the GWP to be 4.2% higher than the verified EPD projected. The NRMCA tool was much closer of an estimation to the verified EPD, and was also a relative conservative estimate.
For the concrete mixture represented by the circular marker, the OpenLCA estimated GWP 5.2% lower than the verified EPD projected. The NRMCA tool estimated the GWP to be 18.8% higher than the verified EPD projected. The OpenLCA tool was much closer of an estimation to the verified EPD, but was a less conservative estimate.
What does this mean?
What does this mean?
There is no substitute for developing an ISO-conformant, verified EPD. However, these free estimating tools can provide an initial indication of concrete mixture GWP while working towards developing an ISO-conformant, verified EPD for that concrete mixture. EPDs that are product-, facility-, and supply-chain specific will provide more precise estimations of your concrete mixture's environmental impacts.
There is not one estimating tool that is more appropriate than another for all concrete mixtures or all scenarios. Both the OpenLCA tool and the NRMCA tool can provide indicators of the GWP associated with a concrete mixture. NRMCA - who is the program operator for the Concrete PCR - specifically identifies that the Theta and Climate Earth tools for developing an ISO-conformant EPD are the ONLY verified methods.
We recommend that the user utilize the tool that allows them to input the most project-specific data available to them. For example, if only the concrete mixture proportions are known, the NRMCA tool may be a better choice for an initial indication of the concrete mixture's GWP. However, if transportation distances of the constituents, mixture proportions, and some production data is known, the OpenLCA may be a more appropriate choice of tools for estimating the concrete mixture's GWP.
What could cause this disparity?
What could cause this disparity?
This disparity in estimations from the various tools can be caused by a variety of factors:
facility-specific vs. industry-average constituent production efficiencies
actual vs. estimated or average transportation distances
actual vs. suggested fuels used for processing
transportation efficiency
SO WHAT SHOULD I DO? - Use the tools available to estimate concrete mixture GWP while working towards developing an ISO-conformant, verified EPD for that concrete mixture. EPDs that are product-, facility-, and supply-chain specific will provide more precise estimations of your concrete mixture's environmental impacts. It is better to have an indicator to compare a mixture to than to not quantify at all!
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