Hello community members - are there resources for how to lower the embodied carbon impact of specifically precast concrete elements? Do EPDs for precast concrete elements exist? Would ready-mix data be representative for precast, or not?
Thanks for your insight & time,
Hi Alex, here are a few resources I know of:
PCI has EPDs for industry average precast, although I think they just expired: EPDs and Your Plant - National Precast Concrete Association
It looks like Clark Pacific has EPDs for some of their precast members now, but it doesn’t seem like there are many supplier specific EPDs yet.
Most precast suppliers I’ve talked to use Type III cement. The quick strength gain of this cement is important for their turn around time. I’ve used this EPD from LeHigh before to try to compare the impacts of different types of cement: LehighCementUnBridPack_NRMCAEPD_20043Final20210501.pdf
Precasters can cure concrete in carbon-rich environment. Not exactly sure how this is done, but it sequesters some CO2 and increases strength. Probably more reliable than liquid CO2 injection. The RMI concrete guide described this tech. https://rmi.org/insight/concrete-solutions-guide/. For precast wall panels, there is innovation around thin shell systems that can reduce the volume of concrete. Our rough estimates show ~20% reduction from typical sandwich panel (great, but not as great as might be claimed by mfrs).
Hi - this is NOT a direct answer to your question, but may be useful down the road. We’ve been talking to a few new companies who are providing sources for substitution for both concrete and precast elements that reduce EC and also sequester (some of these are biochar-based and other approaches). I’ve encouraged them (of course) to get EPDs and we will be sharing their info as soon as we do more vetting (and of course if BuildingGreen assesses them - they will publish that info too!). Good to know that there is change out there that we can look forward to!