PSI - Issue 64

Shaofeng Qin et al. / Procedia Structural Integrity 64 (2024) 168–174 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 3. (a) the electrical response change in resistance during cyclic flexural loading, and (b) the maximum change in the resistance versus the different loading conditions for the three groups.

4. Conclusions The study investigated the effect of fiber alignment on the electrical properties of commercialized chopped CFs under cyclic flexural loading. The alignment of the fibers was controlled using extrusion-based 3D printing technology. The results showed that fiber alignment parallel to the printing direction led to higher conductivity in certain measured regions and possibly higher flexural strength with higher deviation. During cyclic flexural loading, the fractional change in resistance was stable for all groups with or without aligned carbon fibers when the loading was relatively low (less than 10N). However, as the loading increased, the fractional change in resistance of the groups with aligned carbon fibers (LCF) became more sensitive to plastic deformation, followed by the medium-aligned carbon fiber group (MCF) and the randomly aligned carbon fiber group (RCF). This phenomenon is related to the percolated network structure of the fibers. References Dong, W., Li, W., Tao, Z. and Wang, K., 2019. Piezoresistive properties of cement-based sensors: Review and perspective. Construction and Building Materials 203, 146-163. Hambach, M., Möller, H., Neumann, T. and Volkmer, D., 2016. Portland cement paste with aligned carbon fibers exhibiting exceptionally high flexural strength (> 100 MPa). Cement and Concrete Research 89, 80-86. Hambach, M., Rutzen, M. and Volkmer, D., 2019. Properties of 3D-printed fiber-reinforced Portland cement paste. In 3D concrete printing technology, Butterworth-Heinemann, pp. 73-113. Li V.C., 2003. On engineered cementitious composites (ECC). Journal of Advanced Concrete Technolohy 1(3), 215 – 230. Li, V.C., 2019. Engineered cementitious composites (ECC): bendable concrete for sustainable and resilient infrastructure. Springer. Rutzen, M., Lauff, P., Niedermeier, R., Fischer, O., Raith, M., Grosse, C.U., Weiss, U., Peter, M.A. and Volkmer, D., 2021. Influence of fiber alignment on pseudoductility and microcracking in a cementitious carbon fiber composite material. Materials and Structures 54, 1-21. Wright, W.J. and Celik, E., 2023. In Situ Electrical Network Activation and Deactivation in Short Carbon Fiber Composites via 3D Printing. Advanced Functional Materials 33(40), p.2303282. Zollo RF., 1997. Fiber-reinforced concrete: an overview after 30 years of development. Cement and Concrete Composits 19(2), 107 – 122.