Barriers Limiting Innovation in Concrete Carbon Reduction

Abstract

On a unit mass basis, concrete has one of the lowest carbon footprints and embodied energy of all manufactured materials. However, because concrete is humankind’s most widely used material, it is one of the largest single sources of anthropogenic greenhouse gas (GHG) emissions being responsible for approximately 0.7% of the total U.S. greenhouse gas emissions in 2020 and roughly 7% of the total GHG emissions worldwide. The largest contributor to the GHG emissions associated with concrete is the production process of portland cement clinker. Therefore, reducing the clinker content in concrete is the best near-term method for reducing its carbon footprint. Numerous technologies exist that could, if implemented, provide immediate reductions in the carbon footprint of cement and concrete, but every concrete product is made differently, using a wide variety of local materials and mixture proportions, and is designed for specific fresh, hardened, and durability properties depending on application. Because of this, innovations will need to be tailored for the specific concrete mixture and application. Furthermore, several roadblocks within the industry prevent these technologies from being used, with the overarching roadblock being risk-aversion. Without a fair distribution and deep understanding of the risk associated with innovation, new materials and methodologies cannot move forward. This presentation will discuss the current state of the cement and concrete industries, identify barriers to innovation that limit efforts for meaningful carbon reduction, and describe an action plan to address these barriers.