Monitoring of building structures from braided composite reinforcing bars (BCRs)

Abstract

The present work arises from a study in which piezoresistive braided composite rods (BCRs) were developed by incorporating a glass fibre filament impregnated with carbon nanotubes (CNTs). Different mass concentrations of CNTs [0%, 0.5%, 1%, 1.5%, 2% and 2.5%] were dispersed in epoxy resin and polylactic acid (PLA) polymer formulations. These formulations were then used to impregnate the glass fibre filaments with alkaline pre-treatment. The alkaline pre-treatment effect of the BCRs glass fibre filaments was characterised by Fourier-transform infrared spectroscopy (FTIR) technique. The piezoresistive performance of the functionalised BCRs was evaluated using a dedicated set-up to, simultaneously, measure the mechanical strain and electrical resistance variation response, during cyclic tensile loads. Through the results, it was found that the obtained structural piezoresistive sensor presents a suitable sensitivity to replace high density and oxidation susceptible steel bars in concrete reinforcement with a smart monitoring structure.