Issue 40

Z.S. Metaxa et al, Frattura ed Integrità Strutturale, 40 (2017) 61-73; DOI: 10.3221/IGF-ESIS.40.06 61 Focussed on Recent advances in “Experimental Mechanics of Materials” in Greece Strain monitoring of cement-based materials with embedded polyvinyl alcohol - carbon nanotube (PVA-CNT) fibers Zoi S. Metaxa National Technical University of Athens, Laboratory of Strength and Materials, 9 Heroes Polytechnion Str., 15780 Athens, Greece Wilfrid Neri, Philippe Poulin University of Bordeaux, Centre de Recherche Paul Pascal – CNRS, Avenue Schweitzer, 33600 Pessac, France Nikolaos D. Alexopoulos University of the Aegean, Department of Financial Engineering, 821 00 Chios, Greece nalexop@aegean.gr A BSTRACT . This article investigates the possibility of exploiting innovative polyvinyl alcohol fibers reinforced with carbon nanotubes (PVA-CNT fiber) as a strain sensor in cement mortars used in the restoration of Cultural Heritage Monuments. Two types of PVA-CNT fibers were embedded in the matrix at a short distance from the bottom of the beam and their readings were correlated with traditional sensors, e.g. strain gauges and Fiber Optic Bragg Gratings. The Electrical Resistance Change (ERC) of the embedded PVA- CNT fiber was in-situ monitored during four-point bending mechanical tests. For the case of coated PVA-CNT fiber, a linear correlation of the applied strain at the bottom surface of the specimen along with ERC values of the fiber was noticed for the low strain regime. For the case of incremental increasing loading – unloading loops, the coated and annealed PVA-CNT fiber gave the best results either as embedded or as ‘surface attached’ sensor that exhibited linear correlation of ERC with applied strain for the low applied strain regime as well as hysteresis loops during unloading. The article discusses their high potential to be exploited as strain/damage sensor in applications of civil engineering as well as in restoration of Monuments of Cultural Heritage. K EYWORDS . Cement-based materials; Sensing; FOBGs; Monitoring. Citation: Metaxa, Z.S., Neri, W., Poulin, P., Alexopoulos, N.D., Strain monitoring of cement-based materials with embedded polyvinyl alcohol - carbon nanotube (PVA- CNT) fibers, Frattura ed Integrità Strutturale, 40 (2017) 61-73. Received: 19.01.2017 Accepted: 10.03.2017 Published: 01.04.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.