One of the most promising technologies for structural health monitoring of civil structures and infrastructures is that of fiber optic sensors (FOS), serving as both sensor and data conduit. Nevertheless, many challenges associated with their use in real-world cases have not been fully solved yet, mainly relating to the application methodology and the long-term properties under severe environmental conditions. This paper presents the development and testing of smart composite rods, composed of carbon fiber reinforced plastic (CFRP) material with embedded Fiber Bragg Grating (FBG) optical sensor. The rods are manufactured using a modified pultrusion process, allowing both the FBG sensor embedding within the composite and the subsequent recovery of the associated fiber-optic leads. The rod packaging gives to the optical fiber the necessary protection against an accidental damaging during handling and installation, allowing, at the same time, structural strengthening of the structure. The rod, which can be considered as a new sensor, is to be applied inside a groove specifically prepared on the concrete element, or applied as a conventional internal reinforcing rebar. Tensile and flexure tests were carried out and the strain measures from the FBG sensors were compared to data obtained from conventional surface mounted electrical strain gauges, in order to calibrate the transfer function of the smart rod. Physical characterization of the smart rod was carried out through microscopy analysis, while the in-situ applicability of the new sensor was demonstrated on a motorway RC bridge structure, in the framework of the seismic upgrade intervention on the bridge by means of FRP materials. The performed work allows concluding that the developed solution can be considered a good candidate for contemporary strengthening/monitoring of civil infrastructures.
|Titolo:||Development and testing of smart CFRP rods for structural health monitoring|
|Data di pubblicazione:||2009|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|