Description
In this paper, we present the application of distributed fibre optic sensors (DFOS) for the detection of bending and shear cracks in reinforced concrete beam specimens loaded in three- and four-point bending in lab conditions. The main goal of this study is to prove the feasibility for future application of DFOS for monitoring of existing concrete structures such as bridges or tunnels. Each specimen was equipped with more optical fibres: most of them were attached in the channels at the outer surface of the specimens and some of them were fixed to the reinforcement inside the specimens. Specimen geometries, arrangement of reinforcement bars and loading schemes of the specimens were determined by nonlinear FEM before the tests, so that either dominant bending or dominant shear cracks appear during the loading. Some specimens were loaded step-by-step and some of them by continuous loading and the results were compared afterwards. The results showed, that DFOS can ensure exact crack monitoring in all loading stages of the reinforced concrete specimens, which is a good basis for future applications for monitoring of structures in the engineering practice.
