What have the Romans ever done for us?

Invented sustainable concrete, that’s what

It’s the Monty Python sketch that just keeps on giving. A paper published in January 2023 in Science Advances (Vol 9, issue 1) made headlines at the start of the year. The study suggests a reason why several ancient Roman structures are still standing today, over 2,000 years since their construction. The authors posit that small lumps of lime clast found in the mixed mortar, that had previously been thought to be the result of poor mixing, may in fact have been added intentionally during a hot mixing process; with the result that any cracks would allow water to reach these clasts, which would then dissolve and expand to fill the cracks – ultimately creating self-healing concrete. The authors go on to say this could pave the way for the development of more durable, resilient and sustainable concrete formulations.

At DDK, we have two proprietary Carbon Analysis Models. The first is used to manage and optimise the embodied carbon in the construction phase and the second to optimise operational energy usage and Scope 1 carbon footprint. We can see from our models that the carbon from concrete is usually more than 30% of the embodied carbon in a typical factory build. This is because the cement used to make concrete is a highly carbon-intensive product, with one tonne of carbon dioxide created for every tonne of OPC (ordinary Portland cement) produced. In fact, cement currently represents around 8% of the total global carbon footprint.

Modern concrete is prone to cracking and breaking and often requires extensive in-life repair, which adds to total carbon emission; and given it has an expected lifespan of 50-100 years – it’s certainly not up to Roman standards.

What are the other approaches are there to reduce construction carbon? Using DDK’s sustainability models and applying critical thinking to building design and the approach to construction, enables clients to plan to minimise the build’s carbon footprint to the lowest possible level.

Romani ite domum indeed – they’re probably still standing.