World's first carbon neutral concrete bridge revealed

[Peterpetrole]

Pretty inspiring stuff I'm sure you'll all agree, I love a nice bridge

"The structure, built by by construction firm Heijmans and materials company Paebbl, uses a combination of Paebbl’s carbon‑storing material, biochar and recycled aggregates. The project partners said the mix contains 75% circular raw materials and contains no primary sand or gravel.

According to the consortium behind the project, 30% of the cement in the concrete was replaced with Paebbl’s material, and the resulting deck permanently sequesters about 66kg of CO₂. They report an embodied‑carbon reduction of nearly 30% compared with a low‑carbon reference concrete."

Picture of the bridge down the bottom of the page:













































https://www.newcivilengineer.com/latest/worlds-fir...

[kambites]

Cement production is very energy intensive, so if they've really managed to make it carbon neutral that's actually quite an achievement. I must admit that when I read the title I was imagining something a bit more... grand, though. The best way to make a bridge that size carbon neutral would probably be to not make it out of concrete.

[marksx]

Did they dig a hole just to build a bridge??

[TA14]

marksx said:

Did they dig a hole just to build a bridge??

Ha ha. I wondered that. I assume that it will be an ornamental lake or some SUDS swale etc..

[John D.]

I love a nice bridge too. That one is pathetic!

[Dave Hedgehog]

marksx said:

Did they dig a hole just to build a bridge??

it does look like a proof of concept

[rodericb]

It looks like they managed to reduce carbon emissions by around 20% with the path on either side of that bridge too.

[Hoofy]

I was expecting something slightly larger like the Golden Gate bridge.

[AmyRichardson]

Got to start somewhere...

I saw 66kg sequestered and thought "66kg/ton?" But no, just 66kg makes sense.

[Night Owl]

Why would anyone want the world to be "carbon neutral"?

[Simpo Two]

I think we first made bridges that size in about 1,000 BC.

What are 'circular raw materials' and how much more expensive was that bridge than a normal one?

As ever the West (well Europe) chases carbons and puts other practicalities aside to tick an eco PR box and get their photo on page 11 of 'Practical Carbon Weekly' as they collect a worthless trophy for 'best eco-bridge' (the trophy is plastic and made in China because it's too expensive to make them here for some curious reason).

Unimpressed of Tunbridge Wells. Bah.

[768]

AmyRichardson said:

Got to start somewhere...

I saw 66kg sequestered and thought "66kg/ton?" But no, just 66kg makes sense.

I made the same leap, not sure how I didn't cotton on before the reveal.

They could have just put a few logs across for that, planted some trees and called it carbon neutral.

[boyse7en]

Jeez, tough audience.

It's a proof-of-concept project using a new material that may be applicable to larger scale projects in the future. Using the new material in a bridge gives an implicit confidence in its structural strength.

[JoshSm]

Simpo Two said:

What are 'circular raw materials' and how much more expensive was that bridge than a normal one?

Crushed waste I'd assume?

[JoshSm]

Ok, so if you've replaced 1/3 of the cement, what is the cost and the structural performance impacts?

Lots of places skimp on cement, doesn't mean it's a great idea.

Benefits don't seem massive to be honest?