Structural health monitoring of new bridges by distributed fiber optic sensors embedded in concrete

A research project focusing on a newly erected major highway viaduct in Austria explores a new concept, where distributed fibre optic sensors (DFOS) are embedded in concrete already during construction to support the condition assessment of the bridge later on, for example during the visual inspections carried out at regular intervals. Fibre optic cables for strain and temperature measurements were embedded in the side span of the bridge, which is erected partly by the balanced cantilever method and partly on falsework. Measurements were taken at different construction stages, during the dynamic excitation of the superstructure and under traffic conditions tracking passing heavy vehicles on the structure. The experiences gained from this pilot application are presented exploring the possibilities of DFOS, highlighting its benefits but also pointing out challenges and risks.