PSI - Issue 64

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Author name / Structural Integrity Procedia 00 (2019) 000 – 000

Antonella D’Alessandro et al. / Procedia Structural Integrity 64 (2024) 1160–1167

1166

Fig. 5. (a) Small-wall subjected to a compressive load of 2 kN, (b) capacitance between pairs of electrodes and (c) fractional change in capacitance of smart-wall for the pair electrodes named C1 6. Conclusions The paper has presented an investigation of electrical and sensing performance of cement-based mortars with carbon microfibers for application in strain and damage detection of masonry structures. In particular, the doping effect and the different sensing measurement method have been preliminarily analyzed for a future in-depth research on higher scale and tailored configurations. The piezoresistive and piezocapacitive responses of normal and smart mortars doped with carbon fillers at 0.025%, 0.1%, and 0.25% were evaluated using a 1 Hz biphasic excitation signal. In that sense, smart-mortars elucidated high stability in the piezocapacitive response with noise standard deviation comprised between 2.3% and 2.5% of the mean value; specifically, the 0.25% specimens showed an excellent sensitivity in the fractional change of capacitance of - 1.3, with a compressive load of 4 kN, corresponding to a stress value of 2.5 MPa. Hence, the findings, along with the methodology employed to acquire piezoresistive and piezocapacitive measurements, hold promise for structural health monitoring applications in masonry structures. In particular, these results, part of the FIS2021 Advanced Grant “SMS SAFEST” project, represent an initial step in designing a conductive mortar for smart masonry, paving the way for real-scale applications of tailored monitoring systems for masonry structures. Acknowledgements The authors would like to gratefully acknowledge the support of the Italian Ministry of University and Research (MUR) via the FIS2021 Advanced Grant “SMS -SAFEST - Smart Masonry enabling SAFEty-assessing STructures after earthquakes” (FIS00001797). Dr. Meoni also acknowledges the European Union - NextGenerationEU and the University of Perugia for supporting his research activity through the project Vitality framed within the Italian Ministry of University and Research (MUR) National Innovation Ecosystem grant ECS00000041 – VITALITY. References Azhari, F.; Banthia, N. Cement-based sensors with carbon fibers and carbon nanotubes for piezoresistive sensing, Cem. Concr. Comp. 2012, 34, 866-73 Baeza, F.J., Chung, D.D.L., Zornoza, E., Andión, L.G., Garcés, P. Triple Percolation in Concrete Reinforced with Carbon Fiber. ACI Mater. J. 107 (2010) 396-402. Banthia, N., Djeridane, S., Pigeon, M. 1992. Electrical resistivity of carbon and steel micro-fiber reinforced cements. Cem. Concr. Res. 22 (1992) 804-814. https://doi.org/10.1016/0008-810 8846(92)90104-4 Birgin H.B.; D’Alessandro, A.; Laflamme, S.; Ubertini F. Hybrid carbon microfibers -graphite fillers for piezoresistive cementitious composites. Sensors 2021, 21 (2), art. no. 518, pp. 1 - 13, DOI: 10.3390/s21020518