Distributed Deflection Measurement of Reinforced Concrete Elements Using Fibre Optic Sensors

The construction of new infrastructure required to meet the demands of a growing global population has substantial negative impacts on the environment. Structural engineers can help reduce these negative impacts through efficient material use in reinforced concrete (RC) design, as steel and concrete production accounts for a significant portion of global greenhouse gas emissions. In RC design, stiffness and support condition assumptions often lead to large discrepancies between design models and true behaviour. Critical insight would be captured if the deflected shape of RC beams could be practically measured. A method of measuring the deflected shape of RC beams using distributed fibre optic sensors (FOS) is presented. Six RC beams were tested in three-point bending. The FOS results were evaluated against displacement transducers and were found to capture deflected shapes accurately until loading exceeded 50% of the beams’ ultimate capacities.