Experimental analysis of the tensile behaviour of textile reinforced cementitious matrix composites using distributed fibre optic sensing (DFOS) technology

Abstract

This work presents an experimental study of the mechanical behaviour of textile reinforced cementitious matrix composites (TRCMC) subjected to direct tensile loading. Distributed optical fibres embedded in the core of the composites were used as strain sensors. The measurements were based on the Rayleigh backscattering principle. The sensors were able to measure the strain in the specimen during the test at different locations because of their spatial resolution and reduced dimensions and thus make it possible to analyse and identify the behaviour of the matrix, the textile, and the textile/matrix interface. Six configurations were tested and analysed in this study: two types of matrices with three reinforcement ratios.The local and global behaviours were analysed, and the test results during the three typical stages of the mechanical behaviour of TRCMC composites are explained. The parameter controlling the behaviour of the crack propagation phase is identified, and an explanation of its influence on crack distribution is highlighted. The validity of the law of mixtures and the hypotheses of the textile/matrix interface were examined and compared to experimental results. The influence of the reinforcement ratio was also identified. The obtained results allow a better understanding of the local and global mechanical behaviours of TRCMC composites and the assessment of present theoretical hypotheses in literature related to these behaviours.