This is one approach used at Arizona State University to reduce the carbon footprint of its Interdisciplinary Science and Technology facility. The concrete team set out to use a post-consumer byproduct to reduce the total amount of cement in the building structure by at least 40%. “It takes a lot of equipment and resources to produce cement,” said McCarthy Building Companies Senior Project Manager Carlos Diaz. “If you can replace a high percentage of cement with a recycled material like fly ash, you can offset a significant amount of carbon.”
For this mix, concrete producer Hanson Aggregates, LLC, used fly ash (a byproduct from electric and steam generating plants), along with ADVA® and WDRA® concrete admixtures from GCP Applied Technologies to achieve their sustainability goals. “The ADVA® admixture gave us the opportunity to keep the water/cement ratio low while achieving high strength as well as the workability to place the concrete very easily,” said Bill Wheeler, Quality Control for Hanson Aggregates LLC.