PSI - Issue 64

Wenkui Dong et al. / Procedia Structural Integrity 64 (2024) 1152–1159 Wenkui Dong and Marco Liebscher et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Electrodes configuration with the MCF for electrical and piezoresistivity.

2.4. Configuration for piezoresistivity test Previous studies demonstrated that the 28-day flexural strength of MCF can reach more than 500 MPa after proper curing (Zhao et al., 2023a), hence, the stress magnitude of 48.5 MPa is chosen within the elastic regime to evaluate the piezoresistive behaviors. It was experimentally investigated by the three-point bending test at the cyclic stress magnitudes with three cycles. The cyclic loading was conducted to assess the piezoresistive repeatability and reversibility, which is demonstrated appliable for the assessment of piezoresistivity of cementitious materials (Dong et al., 2020c). Electrical resistance changes of MCF were measured through a SIGLENT SDM3045X digital multimeter with an acquiring rate of 5 data per second. The experimental setup and schematic diagram can be found in Fig. 2.

Fig. 2. Experimental configuration for the piezoresistivity test of MCF

3. Results and discussions 3.1. Electrical resistance

The electrical resistance and resistivity of MCF with outer and inner electrode configurations is plotted in Figs. 3a and 3b, where SO1 to SO4 and SI1 to SI4 mean the serial number of samples with outer or inner electrodes. The MCF with outer electrodes showed a smaller electrical resistance in the range of 1.0- 2.5 Ω, compared to that of inner