PSI - Issue 78

Antonella D’Alessandro et al. / Procedia Structural Integrity 78 (2026) 1887–1894

1893

The relationship between the electrical response and the dt parameter (as defined in Equation 4) was investigated to evaluate damage in the tested samples. Figure 6a illustrates the behavior of the paste sample printed along the longitudinal axis, where a marked decrease in the electrical signal was observed. A comparable pattern appears in Figure 6c, corresponding to the mortar sample printed in the same direction, which also exhibited a substantial electrical drop. The sample fabricated in the transverse direction (Figure 6b) showed an almost linear electrical response, indicating limited sensitivity to crack initiation and propagation, and therefore, reduced suitability for damage detection. a) b)

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

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σ / σ₀

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Fig. 6. Electrical parameter and of the (a) paste printed in the longitudinal direction; (b) paste printed in the transverse direction; and (c) mortar printed in the longitudinal direction. 3. Conclusion Results demonstrated that both electrical and mechanical performance were strongly influenced by the printing orientation and material composition. Cement paste doped with CCMF samples printed in the longitudinal direction exhibited superior electrical conductivity and mechanical strength, attributed to the CCMF alignment following the printing path. On the other hand, transverse orientation and the inclusion of sand in mortar samples compromised fiber alignment and conductive paths, reducing both conductivity and sensitivity to damage. The evaluated samples showed effective capability in detecting crack initiation in longitudinally printed samples, highlighting the potential of this approach for damage detection in 3D-printed cementitious composites. 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 dt