Reforço piezo-resistivo de fibra de carbono e resina epoxídica em peças de concreto

Abstract

Piezoresistive materials exhibit the ability to change electrical resistance when subjected to deformations. Based on this property, sensors can be developed for various functionalities, including structural monitoring. In this scenario, polymer matrix composites combined with fibers, especially carbon and glass fibers, have been studied and discussed for deformation sensor purposes. From this perspective, this work aims to determine the order of magnitude of electrical conductivity of carbon fiber, in line with its piezoresistive property, and primarily to demonstrate the capability of carbon fiber-epoxy composite to be used as a sensor. To achieve this, compression tests were conducted on concrete specimens bonded with fiber and epoxy. For comparative purposes, deformation and force data were collected using an extensometer and four strain gauges to correlate the fiber data with that from the instruments. The results obtained from stress-strain diagrams and voltage variation versus deformation positively indicated the piezoresistive nature of the fiber, along with its sensing capability. Furthermore, limitations were observed regarding the use of strain gauges and the proposed low confinement.