Q: After having Environmental Product Declarations (EPDs) done for each one of your Concrete Masonry Unit mix designs, is there anything in particular that you learned?
-Environmentally Lowering Impacts
Having EPDs for each of our mix designs has really helped us see what factors affect the environmental impacts of our products. One interesting thing we uncovered was that previously valued sustainable attributes, such as recycled content and regional materials, didn’t matter as much as we thought for environmental impacts. What mattered the most was the amount of cement in a mix. Cement content affected most of the impact indicators; global warming potential (GWP), acidification, eutrophication, smog creation and ozone depletion. The less cement we use, the less impact we have. One way to reduce the cement content is to use Supplementary Cementitious Materials (SCMs) such as slag (a by-product of the steel industry, unfortunately not usually a regional material anymore). For easy numbers, let’s take a CMU mix design that uses 10% cement. If we replace 40% of the cement with slag, and we were looking at recycled content, the overall weight of pre-consumer recycled content is only around 4%. But, if we look at the GWP, comparing these 2 mix designs, it is lowered by more than 1/3. There were many other things like this that we uncovered by having EPDs for every mix design. Now, not only do we have our EPDs for the rating systems, we also have an environmental impact baseline and solid direction of how to improve our sustainability moving forward.
Heidi Jandris is a technical expert and trusted voice of the industry. She part of the family business’s 3rd generation, grew up immersed in all things concrete block and worked as a welder at the plant before getting her BArch at Pratt Institute in Brooklyn NY. She is the Sustainability Manager and provides technical and design services for A. Jandris & Sons.