There are many ways to cut the carbon emissions of concrete. One is to mix conventional Portland cement with limestone or other similar materials. Another route is to blend cements with cementitious binding materials such as fly ash from coal-fired power plants and granulated blast furnace slag from iron and steel production. Yet other ways include using microorganisms orenzymes in concrete that soak up carbon dioxide.

The problem is what these formulas do to durability. Low-carbon concrete absorbs more carbon dioxide from the air than conventional concrete, a process that lowers its internal alkalinity and leaves the steel reinforcement inside more vulnerable to rust. Because today’s building codes are written to prevent exactly that kind of corrosion, they effectively discourage engineers from using greener concrete in the first place—even though it’s better for the climate.

A new study out of ETH Zurich, published in Nature Communications, offers a way past that impasse. Rather than treating corrosion as a fixed property of a given concrete mix, the researchers modeled how it actually unfolds in the real world. They tested three concrete formulations in four cities with very different climates—Zurich, Bergen, Manaus, and Huailai—feeding detailed local weather data into a model that tracks how moisture moves through concrete over time and how that moisture drives corrosion.

The finding reframes the problem: climate, not chemistry, is the main variable. Wet concrete can corrode up to 100 times faster than dry concrete, while differences between concrete mixes had a comparatively minor effect. In other words, the same low-carbon concrete that might degrade quickly in a humid, rain-soaked city could hold up fine in a dry one.

That points to a fix that’s more about policy than materials science: building standards that account for local climate, rather than applying identical rules everywhere. As lead researcher Ueli Angst put it, engineers need “a better understanding of how environmentally-friendly types of concrete behave over the long term under different weather conditions.” If codes were calibrated to a structure’s actual location, low-carbon concrete could be deployed far more widely in the climates where it holds up—without waiting for a new chemistry breakthrough first.

Source: Christhiana Albert et al. Rethinking concrete durability for low-carbon concretes through climate-informed corrosion modelling, Nature Communications, 2026.

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