Swedish Researchers Extend Concrete Lifespan by 100 Years

Concrete might finally get a second act, and it could last a century.

Researchers at KTH Royal Institute of Technology in Sweden and Tampere University in Finland have developed a reliable system for reusing structural concrete from demolished buildings. Their new framework gives builders the confidence to incorporate salvaged concrete into fresh construction, extending its useful life by another 50 to 100 years.

Until now, reusing concrete has been a risky gamble. Building codes were written for brand new concrete, and no clear guidelines existed for evaluating whether old materials could still do their job safely.

The research team solved this puzzle by gathering data from two dismantled buildings in Sweden and Finland. They ran thousands of computer simulations that predict how concrete will perform under different conditions, whether it's moving from indoors to outdoors or receiving repair treatments.

Lead researcher Arlind Dervishaj, a doctoral candidate at KTH, explains that their approach relies on real measurements of concrete that's already weathered decades of use. It's not guesswork based on generic rules but actual performance data that makes accurate predictions possible.

One key discovery involves carbonation, the natural process where rising CO₂ levels reduce concrete's protective alkalinity. When concrete moves from a dry indoor space to a humid outdoor environment, this process accelerates and can cause the steel reinforcement inside to corrode.

But here's the exciting part: simple treatments can make a massive difference. Applying water-repellent or silicone-based coatings can slash corrosion rates by up to 70%, keeping concrete structurally sound for decades longer.

The Ripple Effect

Construction accounts for a staggering amount of global carbon emissions, and concrete production is one of the biggest culprits. Keeping existing concrete in use instead of crushing it and pouring new batches could dramatically reduce the industry's environmental footprint.

Kjartan Gudmundsson, who heads KTH's Division of Sustainable Buildings, calls it a pathway to circular construction. "Reusing concrete is one of the most effective ways to cut emissions," he says. The framework gives designers and engineers practical tools to make informed decisions that reduce waste while keeping materials circulating in the economy.

The research has already influenced real-world projects. In 2022, researchers designed a demo pavilion in Helsingborg, Sweden, constructed entirely from salvaged precast elements from local demolished buildings.

Both Gudmundsson and Dervishaj now serve on the Swedish Standards Institute committee working to establish national standards for reusing precast concrete products. These standards would cover everything from floor slabs and beams to columns, walls, and stairs.

Even concrete that's served faithfully for decades can be assessed, refurbished, and safely put back to work with the right approach.