Abstract

Here we present our latest efforts in the development of functionalized carbon reinforcement structures (FCSs). FCSs are textile based carbon structures that are functionalized with optical fibre sensors and are designed for the reinforcement as well as structural health monitoring (SHM) of concrete composites. A schematic of a FCS is shown in Fig. 1a. In this example, the FCS contains an optical glass fibre to measure distributed strain profile using the Optical Frequency Domain Reflectometry (OFDR) technique as well as two Fibre Bragg Grating (FBG) sensors to determine local strain and strain direction. The fabrication technique to manufacture FCS has been developed at the Saxon Textile Research Institute (STFI) in Chemnitz, Germany, and the fabrication of the FCS involve embroidering of the carbon fibre filaments and optical glass fibres simultaneously on a polyvinyl alcohol (PVA) nonwoven substrate [1]. PVA was chosen as an embroider substrate since it can be easily removed by dissolving it in hot water and the dissolved PVA further stabilizes the FCS. A manufactured FCS that is embedded in a custom-made concrete block in order to evaluate the sensor performance of the FCS is illustrated in Fig. 1b. After the concrete was set, the concrete blocks containing the FCS were installed in a three point bending test rig (Fig. 1c) and the load transfer from the concrete to the FCS was observed using the integrated optical fibre sensors. In Fig. 1d, the response of the FBG sensor inside the FCS in response to the applied load is illustrated for three consecutive load cycles.

© 2019 IEEE