Table 4 Evaluation results on the validation concrete decks by various survey methods.
Location | Visual inspection | GPR | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Survey area (m2) | Damage | Survey area (m2) | Relative permittivity | Depth-corrected attenuation (normalized, − 3 dB) | |||||||||||
Damage (over 12) (current rule) | Damage (out of 6 ~ 11) (suggested criteria) | ||||||||||||||
Area (m2) | Ratio (%) | Rating | Area (m2) | Ratio (%) | Rating | Area (m2) | Ratio (%) | Rating | Area (m2) | Ratio (%) | Rating | ||||
JB-3N | Span 2 | 336 | 2.4 | 0.7 | b | 271.8 | 3.6 | 1.3 | b | 21.8 | 8.0 | c | 19.9 | 7.3 | c |
Span 3 | 336 | 65.9 | 19.6 | d | 271.8 | 16.8 | 6.2 | c | 52.5 | 19.3 | d | 60.6 | 22.3 | e | |
Span 4 | 336 | 16.8 | 5.0 | c | 271.8 | 49.4 | 18.2 | d | 125.0 | 46.0 | e | 60.4 | 22.2 | e | |
Span 5 | 336 | 8.9 | 2.6 | c | 271.8 | 48.8 | 18.0 | d | 63.8 | 19.0 | d | 48.3 | 17.8 | d | |
Total | 1344 | 93.9 | 7.0 | c | 1087.2 | 118.7 | 10.9 | d | 263.1 | 19.5 | d | 189.2 | 17.4 | d | |
JB-3S | Span 2 | 336 | 3.0 | 0.9 | b | 274.5 | 1.3 | 0.5 | b | 3.4 | 1.2 | b | 23.2 | 8.4 | c |
Span 3 | 336 | 0.3 | 0.1 | b | 274.5 | 3.6 | 1.3 | b | 19.2 | 7.0 | c | 11.2 | 4.1 | c | |
Span 4 | 336 | 5.7 | 1.7 | b | 274.5 | 4.7 | 1.7 | b | 9.1 | 3.3 | c | 21.2 | 7.7 | c | |
Span 5 | 336 | 8.7 | 2.6 | c | 274.5 | 1.6 | 0.6 | b | 6.1 | 2.2 | c | 23.7 | 8.6 | c | |
Total | 1344 | 17.7 | 1.3 | b | 1098 | 11.2 | 1.0 | b | 37.7 | 3.4 | c | 79.3 | 7.2 | c | |