PSI - Issue 67

Daniel A. Triana-Camacho et al. / Procedia Structural Integrity 67 (2025) 47–52 D.A. Triana-Camacho et al. / Structural Integrity Procedia 00 (2024) 000–000

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(a)

(b)

Fig. 4. (a) Capacitance as a function of the compressive stair loading, and (b) the fractional change in capacitance under a compressive strain.

It could be stated that there is limited on the piezocapacitive properties of cement-based composites, but there exist some investigations promising that piezocapacitance has the potential for SHM applications Triana-Camacho et al. (2023); Shi and Chung (2018); Pan and Guan (2022); Chung and Wang (2018). Furthermore, studies related to piezocapacitive properties of asphalt and cement reveal nonlinearity in the fractional change also emerges at low deformations, as highlighted by Oztruk et al.Chung and Wang (2018); Ozturk and Chung (2021). Nonlinearity phenomena can also be observed in piezoresistive cement-based composites when the system is under the percolation threshold Garc´  a-Mac´  as et al. (2017). Therefore, being under the percolation threshold can suppose better linearity for the piezocapacitive response as seen in curve M2, Figure 4(b). Hence, there is a pressing need to deeply explore the piezocapacitance and compare it with the piezoresistance of rGO-cement-based composites searching for further linearity and sensitivity, owing to they could work as strain-based sensors in SHM. Conclusions Piezocapacitance is proposed as a promising self-sensing feature for the production of strain-sensing cement-based composites for SHM applications. As a consequence, a methodological sequence was established to determine the capacitive or piezocapacitive properties of rGO-cement-based composites, which is also applicable to other smart materials. In that sense, this work pretends to encourage researchers to use this kind of electrical characterization for elucidating the electromechanical properties of self-sensing cement-based composites. For supporting this type of characterization, a sensitivity of 23% in fractional capacitance change was found for deformations of 5000 µ ε . In the line of piezocapacitive materials, further research is needed to evaluate the dispersion methods under other physico- chemical characterizations, as the dispersion method of these nanocomposites dramatically a ff ects the linearity of the fractional capacitance change. In addition, tests to demonstrate the e ff ectiveness of rGO-cement-based composites for SHM applications will be conducted in future research activities. Acknowledgments 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 SAFE-ty-assessing STructures after earthquakes” (FIS00001797). Dr. Meoni also acknowledges the European Union - NextGenerationEU and the University of Perugia for supporting the work through the project Vitality framed within the National Innovation Ecosystem Grant ECS00000041.