PSI - Issue 84

Irene Matteini et al. / Procedia Structural Integrity 84 (2026) 677–685

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Scan depth: 30 cm

Scan depth: 35 cm

Scan depth: 40 cm

Fig. 6. C-scan images displaying the first layer of reinforcement and the orthogonal rebars at various depths: (a) 30 cm; (b) 35 cm; (c) 40 cm. The three images above highlight how the orthogonal rebar have been placed at different depths. This could be attributed to poor craftsmanship during construction. The resulting “Cover Map” (Figure 7) further confirms the visual indications of the depth-slices indicating a strong variability in the concrete cover values, shallow on the sides of the bridge and deeper along the longitudinal axis.

Fig. 7: Cover map. Areas in red represent low cover areas, versus the blue area which show a deeper cover. Data from the first survey.