Use of distributed optical fibre as a strain sensor in textile reinforced cementitious matrix composites

This study focused on using optical fibres embedded into the core of textile reinforced cementitious matrix composites (TRCMCs) as strain sensors. These composites have been increasingly used for strengthening and rehabilitating existing constructions and civil engineering structures. Our aim was to assess the embedding capability, strength, and feasibility of strain measurements of a material which exhibited multiple early cracks when loaded in tension. To this end, the Rayleigh backscattering technique was chosen, which allowed performing full field strain measurements with millimetric spatial resolution. Two standard mechanical tests were performed on the composite specimens with embedded optical fibres: the three-point bending test on a cementitious matrix beam, compared to the theoretical results using the beam theory, and a direct tensile test on a textile reinforced specimen, compared to the results of surface strain gauges. These results emphasised that implementing optical fibres using the Rayleigh backscattering technique would be a feasible approach to finely analyse the mechanical behaviour of cementitious matrix composites. (C) 2019 Elsevier Ltd. All rights reserved.