Preface: Has time passed concrete by?

You sometimes hear people talk about the postcement era. This refers to replacing the nearly 200 years old Portland cement with loweremission binders or concrete with some other building materials.

Cement and concrete evolve as materials. The most important driver of their evolution is the aim to curb climate change and reduce carbon dioxide emissions caused by concrete. However, it is not possible to replace concrete, simply because there are not enough other materials.

We have different solutions to reduce concrete emissions. This work is already underway. The cement industry has reduced the use of fossil energy in the production of cement and replaced Portland clinker with admixtures that produce less emissions, such as furnace slag. But this also changes the properties of concrete. One of the biggest challenges with low-carbon concrete is to control the strength development of concrete in the Finnish climate, for example. This requires the efforts of the entire manufacturing chain as well as investments in development and research.

Another significant solution to emission issues is the possibility to recover carbon dioxide at the cement plant.

The low-carbon classification system published by the Finnish Concrete Association does not reduce emissions either, but plays a crucially important role in the transition to low-carbon concrete construction.

Jouni Punkki
Professor of Practice
Concrete technology, Department of Building
Engineering, Aalto University