{"id":24995,"date":"2026-02-20T10:07:54","date_gmt":"2026-02-20T09:07:54","guid":{"rendered":"https:\/\/news.save.ch\/?p=24995"},"modified":"2026-02-20T10:07:54","modified_gmt":"2026-02-20T09:07:54","slug":"neues-verstaerkungssystem-fuer-stahlbetonbruecken-bruecken-sanieren-mit-smartem-stahl","status":null,"type":"post","link":"https:\/\/news.save.ch\/en\/neues-verstaerkungssystem-fuer-stahlbetonbruecken-bruecken-sanieren-mit-smartem-stahl\/","title":{"rendered":"New reinforcement system for reinforced concrete bridges: Renovating bridges with \u00absmart\u00bb steel"},"content":{"rendered":"
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one fiber: The cracks created during the test make the fiber reinforcement in the ultra-high-strength concrete visible. - \u00a9 Empa<\/figcaption><\/figure>\n

Today, bridges are already reinforced with an additional layer of ultra-high performance fiber-reinforced concrete (UHPFRC). This high-performance concrete is applied directly to the roadway slabs and is particularly dense and resistant to water. Conventional reinforcing steel is embedded in it to increase the load-bearing capacity.<\/p>\n

An Empa team led by researcher Angela Sequeira Lemos and Christoph Czaderski from the \u00abStructural Engineering\u00bb department has now gone one step further: they are replacing the conventional steel reinforcement with iron-based shape memory steel (Fe-SMA) - an \u00abintelligent\u00bb material that can remember its original shape. After installation, the bars are heated to around 200 degrees Celsius. As they want to contract but are held back by the concrete, internal tension is created. These internal forces can close cracks, lift deformed elements and extend the service life of a bridge - without the need for complex tensioning devices. \u00abThe beauty of this reinforcement system is its simplicity,\u00bb says Sequeira Lemos. \u00abYou anchor the rods, heat them up - and they do the rest by themselves.\u00bb<\/p>\n

Large-scale tests in the Empa construction hall<\/h3>\n
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Under tension: Empa researcher Angela Sequeira Lemos and her team deliberately caused the concrete slabs to crack in experiments. - \u00a9 Empa<\/figcaption><\/figure>\n

First, the Empa team investigated the interaction between the shape memory steel and the ultra-high-strength fiber-reinforced concrete, which were combined for the first time. The researchers analyzed how well the two materials are bonded together even after the shape memory steel has been heated and what forces can be transmitted.<\/p>\n

This was followed by large-scale tests in Empa's construction hall with five concrete slabs, each five meters long, which simulated self-supporting bridge decks. One slab remained unreinforced, while the others were provided with a layer of ultra-high-strength fiber-reinforced concrete - either with conventional reinforcement or with Fe-SMA bars. In order to simulate real-life conditions, the team first deliberately caused the slabs to crack before they were reinforced - just as would be the case in a real bridge renovation.<\/p>\n

After installation, the researchers heated the Fe-SMA rods, causing them to attempt to contract to their original shape and prestress the reinforced concrete structure. Even during activation, existing cracks visibly closed and remaining deformations completely regressed.<\/p>\n

Significantly stiffer and more durable<\/h3>\n