PSI - Issue 83

Henry Ssenyonjo et al. / Procedia Structural Integrity 83 (2026) 47–56

53

Figure 2. Schematic for (a) Four probe and (b) Two probe for electrical resistivity measurement.

Table 5. Summary of existing studies on the mechanical and piezoresistive performance of self-sensing UHPC

Ref

Additives

Concentration

CS (MPa)

Current mode

ρ (Ω·m) 1.1 × 10⁴ 6.5 × 10³ 3.0 × 10³ 1.3 × 10³ 7.6 × 10⁵ 6.1 × 10⁵ 4.9 × 10⁵ 3.7 × 10⁵ 3.2 × 10⁵ 90.9

GFvalue

2 % (SF) + 0.5% (G)

194.7 180.8

11 20 14 27 28

2% (SF) + 0.375% (G) + 0.125% (CNT) 2% (SF) + 0.25% (G) + 0.25 % (CNT) 2 % (SF) + 0.125% (G) + 0.375% (CNT)

180

DC

(Song et al., 2023)

167.4 166.3

2 % (SF) + 0.5% (CNT)

SF+ G + CNT

0 %

80.3 91.3

-

0.5%

7

1%

105.3 125.7 129.3

3.7 4.6 3.4

DC

(Hou et al., 2022)

SF

1.5 %

2 %

2% (SF) + 0.01% (CNT)

164.9

AC

-

9.6

(Guo et al., 2020)

SF + CNT 3610.7 Available literature indicates that UHPC can deliver high sensitivity under compression when the conductive network and electrode system are appropriately designed. For example, resistance-based studies report synchronized and repeatable responses under cyclic compressive loading for UHPC with stainless or coated fibres (Qiu et al., 2021). Similarly, electrode optimization in UHPC has been shown to markedly increase measured GF and FCR values (Yang et al., 2025). For tensile and crack opening states, hybrid systems incorporating CNTs and steel fibres have demonstrated the ability to simulate tensile stress-strain or stress-crack opening relationships using electrical signatures, enabling both strain and damage sensing in UHPC mixtures (Lee et al., 2024; Zhang et al., 2022). These findings collectively suggest that a single SS-UHPC formulation may need to be tailored to the dominant structural demand (compression-dominated members vs tension/crack-dominated regions) and to the monitoring objective 2% (SF) + 1.24% (CNT) 191 DC -

(strain tracking vs damage state assessment). 6. Factors Influencing Sensing Performance

SS-UHPC signals are sensitive to a wide range of coupled material and environmental variables. Neglecting these influences can lead to misinterpretation of electrical changes as mechanical damage. Key factors influencing the self sensing properties of UHPC have been summarized in Table 6.