Technology to improve the resilience of bridges

said braka 4:50 AM
You can feel it straight away when you drive over

a  quickly: the expansion joint that you rumble over at the start and end of the bridge. These joints are necessary as the bridge expands and constricts depending on the temperature, yet they are also expensive and high-maintenance. However, a type of bridge has now been developed at TU Wien that makes it possible to forego these . The technology was patented and first used by ASFiNAG during the construction of the integral abutment bridge on the A5 North motorway. The bridge without expansion joints has now survived its first winter, with measurement results demonstrating that the new technology works perfectly.
The threat of winter damage
"The bridging of smaller distances with integral bridges is a popular solution – they are monolithic designs with no separate parts that could rub against each other," explains Prof. Johann Kollegger from the Institute of Structural Engineering at TU Wien. This is not usually possible with longer bridges, because the concrete can expand or contract depending on the temperature. Kollegger explains that a bridge that is 100 metres long can differ in length by several centimetres between summer and winter; a difference that is far too great. Particularly in winter, when the concrete contracts, serious damage can occur in the asphalt roadway. This risk is lower in summer, as the material becomes more pliable at higher temperatures.


Read more at: https://phys.org/news/2018-02-technology-resilience-bridges.html#jCp