Micro and macro crack sensing in TRC beam under cyclic loading

This paper studies the ability of self-sensory carbon/glass textile reinforced concrete (TRC) beams to distinguish between micro- and macrocracking. In the proposed configuration, continuous carbon rovings knitted into the textile mesh serve both as the structural reinforcement and as the sensory system. The paper faces the challenge of detecting structural damage within the TRC structure. In this study, damage is defined as the formation of macroscopic cracks, which lead to the accumulation of significant irreversible residual deflection and to a reduction of the relative stiffness of the component. We explore experimentally the correlation between the electrical resistance change and the change of the structural properties and suggests crack detection parameters in order to identify, and mainly to distinguish, between micro- and macrostructural phenomena. Carbon rovings are found to provide electromechanical sensing capabilities, having the ability to distinguish between inner micromechanical structural phenomena and macroscopic ones. These observations are a step towards the applications of SHM techniques by intelligent carbon-based TRC elements.