PSI - Issue 83

Samia M. Mohamed et al. / Procedia Structural Integrity 83 (2026) 72–78

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1. Introduction Road networks are the backbone of modern economies, yet they are aging, heavily loaded, and increasingly exposed to extreme climates. Smart road infrastructure replaces episodic visual inspections with continuous, material-level sensing, turning pavement into a real-time data source for safety and asset management, shown in Fig. 1 (Han et al., 2015). In self-sensing cementitious composites (SSCCs), conductive fillers such as carbon nanotubes, graphene derivatives, carbon black, or metallic fibers create an internal electrical network whose bulk resistivity changes with strain, cracking, moisture, or temperature, allowing the concrete itself to act as the sensor rather than relying on discrete transducers(Bekzhanova et al., 2021a; Dong et al., 2023). Self-sensing in cementitious composites is governed primarily by piezoresistivity, whereby microcrack opening/closure, fiber bridging, and contact/tunneling variations perturb the percolated conductive network and produce measurable changes in bulk resistance (Shahzad et al., 2023). Sensitivity is maximized near the electrical percolation threshold and depends on achieving stable dispersion via polycarboxylate superplasticizers, suitable surfactants, and high-shear/sonication; hybrid systems that combine nano-carbon with short steel fibers can simultaneously enhance sensitivity, toughness, and workability. Electrical response is typically measured using two or four-probe methods (Wang et al., 2024) as shown in Fig 1 (the latter mitigating contact-resistance artifacts) and by alternating-current (AC) interrogation i.e., applying a small sinusoidal signal and analyzing the impedance spectrum most commonly via electrochemical impedance spectroscopy (EIS) to separate bulk, interfacial, and moisture contributions and to track hydration and microstructural evolution (Abedi et al., 2021; Han et al., 2017).

Fig. 1 Probes used in SSCCs (Wang et al., 2024)

Fig. 2 Smart-road use cases enabled by SSCCs, structural health, traffic/WIM, and environmental sensing, linking material transduction to analytics and decisions(Han et al., 2015).

Road and bridge-deck environments are compelling use cases because distress accumulates over areas and under harsh exposures that point sensors may miss; SSCC overlays and patches enable areal monitoring of traffic-induced