CO₂ savings with fibre reinforcement: a worked example

Sustainability claims are only convincing when backed by figures. In this article, we use a concrete real-world example to show how much CO₂ saving fibre reinforcement can deliver compared with traditional steel reinforcement.

Why is steel reinforcement CO₂-intensive?

The production of reinforcing steel requires significant amounts of energy: from mining and processing ore to smelting and rolling steel. This makes steel, kilogram for kilogram, one of the more CO₂-intensive construction materials. Every kilogram of steel reinforcement replaced by a lighter, less CO₂-intensive alternative therefore delivers a direct environmental benefit.

The worked example: foundations for tree and planter boxes

In a recent project, the foundation for tree and planter boxes in public space was redesigned: from traditional steel reinforcement to fibre reinforcement. The results:

• A net saving of 1,500 kg of reinforcing steel through the switch to fibre reinforcement.

• A 98% CO₂ reduction compared with the original steel solution.

• Redesign turnaround: two days, including approval from the municipality.

This example shows that the CO₂ gain lies not only in avoiding steel production, but also in the fact that the required quantity of fibre material per cubic metre of concrete is many times lower than the quantity of steel it replaces — fibres are dosed in kilograms per m³, whereas steel reinforcement in the form of bars and mesh represents a much greater physical weight per m³ of concrete.

Why is the saving so large?

The 98% CO₂ reduction in this example is made up of two factors:

• Avoided steel production: every kilogram of steel that does not need to be produced saves the full CO₂ footprint of steel mining, smelting and processing.

• Limited CO₂ impact of the fibre itself: synthetic fibres also have a production footprint (they are, after all, petrochemical), but this is considerably lower than that of the quantity of steel replaced, partly because far less weight is needed to achieve the same effect.

How does this translate to larger projects?

This particular example concerns a relatively small-scale application (foundations for street furniture). For larger projects — industrial floors, foundations, hard-surfacing — the same principle applies, but the absolute saving scales with the quantity of steel replaced. A floor of several thousand square metres, which would traditionally require tens of tonnes of reinforcing steel, can therefore deliver a considerably larger absolute CO₂ saving than this small-scale example.

How do you use this kind of worked example?

For clients who need to report within, for example, the CO₂ Performance Ladder, a building's MPG calculation, or municipal sustainability targets, a concrete, project-specific worked example is more valuable than a general claim. Always ask a fibre supplier for:

• The exact quantity of steel replaced (in kg) for your specific design.

• A comparative CO₂ calculation between the traditional and the fibre reinforced variant.

• Substantiation that aligns with standard calculation methods (as included in the National Environmental Database).

In summary

The worked example of the tree and planter box foundation shows that the CO₂ saving from fibre reinforcement compared with steel can be considerable — up to almost complete avoidance of the steel-related emissions in comparable applications. For a concrete picture for your own project, a project-specific calculation is needed.

Would you like a CO₂ worked example for your own project? Dutch Fiber Trading will calculate it for you free of charge.

Sources

• Dutch Fiber Trading, project case studies (dftrading.eu/projecten)