Revolutionary New Concrete Bricks Are Made From Demolished Buildings and Air

What if we could use renewable concrete bricks to build new structures? It may not seem like it, but construction is one of the biggest drivers of greenhouse gas emissions that could cause global temperatures to rise over time. But a new process first revealed in 2021 could soon change that.

This new processled by researchers from the University of Tokyo, is called the Calcium Carbonate Circulation System for Building, or C4S. Construction remains such a large driver of climate change due to the high temperatures needed to heat limestone – one of the most important ingredients of Portland cement – ​​enough to produce calcium.

However, by creating renewable concrete bricks, we could reduce the amount of greenhouse gases produced because we wouldn’t have to produce as much calcium from the limestone itself. Instead, we could simply reuse the bricks and construction waste that have already been created and turn them into new bricks.

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It would also help in light of the fact that limestone is currently an infinite resource. Like many other valuable resources we rely on in various human-powered industries, we will eventually run out of it. But with C4S, scientists can combine construction waste and CO2 from the air to create calcium carbonate concrete.

The blocks they made in 2021 were originally relatively small and fragile compared to regular brick blocks. But recently, scientists took concrete from a demolished school building and ground it into a fine powder, which they then mixed with CO2 over the course of three months to create renewable concrete bricks.

The result was a brick pressed from a calcium bicarbonate solution, which was also placed in a mould and then heated to form a new block, which is reportedly large and strong enough to be used in the construction of residential houses and even for paving pavements.

It’s a huge step toward creating proper renewable concrete bricks, and the company hopes to build a two-story house using the new bricks by 2030. Other companies are also looking at ways to revolutionize the concrete industry — one company has even produced concrete that is completely cement-free. The C4S research is available in the journal Advanced concrete technology.