How to find emission factors for recycled concrete aggregate

Hi everyone, I am trying to learn how to compare the embodied carbon of concrete with natural aggregate vs concrete with onsite recycled aggregate. I found CarbonStar, which provides the methodology. But I don’t know where to source the emissions factor for recycled aggregate. Would a custom EPD need to be generated?

Probably a silly question but I’m more familiar with the vertical building world where recycling concrete onsite for aggregate isn’t common. I’m hoping the contractors have more context from horizonal infrastructure projects.

“Not a silly question at all - for recycled aggregate, emissions factors can vary widely by location and processing method. If a generic EPD isn’t available, a custom EPD or data from local recyclers might be your best bet. Contractors working on roads or civil projects may definitely have more insight.”