Spot checks by the Finnish Transport Agency FTA, have revealed deficiencies in the concrete used in at least six bridges.
FTA conducted the tests on 18 road bridges constructed between 2011 and 2016. The strength problems were discovered in six bridges dotted across the country.
The analyses involved testing concrete samples for compressive strength, density and air content. However the agency was not able to identify any common factor linking the concrete used, contractors or bridge type.
On Monday, the agency announced that it would expand its tests to include rail bridges.
Problems may affect service life
According to the FTA, it identified weaknesses at the Autovarikko bridge in Tampere, the Veitikka bridge crossing in Rovaniemi, the Suopellonpolku underpass in Oulu, the Niemenranta underpass in Oulu, the Västersundom bridge crossing in Vantaa and the Takamäki bridge crossing in Seinäjoki.
FTA said that the bridges are safe to use, however the strength problems may affect their service lifetime. Ordinarily, bridges are designed to last 100 years.
The agency said it plans to analyse more concrete bridges built between 2011 and 2016. It will also take samples from up to ten older structures to better understand the impact of any additional materials used in the concrete mix.
The results of the additional tests and possible related recommendations will be available early this year. However FTA said that it intends to step up supervision of bridges already under construction.