Fly Ash and Innovation in Concrete

As climate accountability intensifies, real estate developers, sustainability teams, and procurement leaders face increasing pressure to demonstrate near-term progress alongside long-term net-zero targets. One of the biggest (and often overlooked) levers? Embodied carbon in buildings. While operational emissions have long been the focus of decarbonization strategies, there’s a growing realization that the materials used to construct our buildings carry a significant—and immediate—carbon cost. And those decisions are being locked in right now.

Atmospheric carbonation (sometimes referred to as weathering or “natural” carbonation), which is the absorption of CO2 into hardened concrete over the course of decades, should not be confused or conflated with early-age carbonation, which is the injection and immediate mineralization of captured CO2 in fresh concrete. To put it another way, there is a misperception that CO2 injection just speeds up or supplants the natural process of carbonation in concrete, but this misses key differences between them and how the latter is moving the needle on concrete decarbonization.