Two-dimensional strain measurement and crack detection of reinforced concrete using fiber optic sensors

To ensure reliable service life prediction of reinforced concrete (RC) bridges, it is essential to gain a profound understanding of the progressive damage induced by traffic loading. While computational models are improving, they still require significant resources – especially when analyzing millions of load cycles – and uncertainties in the actual loading situation and material properties further complicate strain and stress assessments. Thus, for a computationally efficient evaluation of the structural condition and lifetime prediction, data directly obtained from the structure proves highly advantageous, as it can be analyzed using simple engineering models. Based on this idea, the authors proposed a monitoring strategy using an externally installed fiber optic sensor network (2D-FOS) for continuous, high-resolution strain measurement. This paper presents initial results demonstrating its effectiveness in precisely tracking strain and crack opening evolution in 2D.