Moisture sensor gives wooden bridges longer life

Published: 26 October 2017

Potential moisture damage on wooden bridges can be detected in time thanks to a new moisture sensor for condition monitoring. The results are now presented in a doctoral dissertation by Niclas Björngrim at Luleå University of Technology in Skellefteå.

– A damage to a bridge that leads to elevated moisture content ​​can be found in good time thanks to the moisture sensor I developed. This allows the bridge to be repaired before the moisture causes rot. On one of the bridges we studied we could find a moisture pocket that occured due to a design miss, the problem could be corrected before the wooden details needed to be replaced, says Niclas Björngrim, who now has a doctorate degree in Wood Science and Engineering at Luleå University of Technology.

Ready to be included in manufacturing

The sensor consists of non-insulated electrodes running along the entire depth of the wood deck to detect possible moisture. It can be used for wood constructions in general, not just bridges.

– Thanks to the moisture sensor, wooden bridges and other wooden structures can become more competitive compared with other materials thanks to ensuring that the technical life span is achieved. The sensor is ready to be used in manufacturing, where it can be installed during the production at Swedish wooden bridge manufacturers.

EU Structural Funds and Formas have financed the research. RISE (formerly SP Wood) has been a partner.