Table 3 Drilling resistance and drilling resistance index (\(K\)) of the sandstone and clay brick samples before and after deterioration.
Deterioration cycle times | 2 | 4 | 6 | 7 | 8 | |||
|---|---|---|---|---|---|---|---|---|
Sandstone samples | Deterioration depth (mm) | 3.9 | 5.6 | 7.4 | 5.3 | 5.6 | ||
Drilling resistance (N) | Undeteriorated | Mean | 27.49 | 28.66 | 27.43 | 26.87 | 28.36 | |
| Â | Â | Standard deviation | 0.48 | 0.92 | 1.20 | 0.56 | 1.30 | |
| Â | Deteriorated | Mean | 24.13 | 21.39 | 17.28 | 15.10 | 12.90 | |
| Â | Â | Standard deviation | 0.73 | 1.18 | 0.96 | 1.24 | 1.08 | |
\(K\)(%) | Â | Â | 12.22 | 25.37 | 37.00 | 43.80 | 54.51 | |
Deterioration cycle times | 3 | 6 | 9 | 12 | 15 | |||
Clay brick samples | Deterioration depth (mm) | 4.4 | 3.6 | 3.8 | 4.8 | 3.5 | ||
Drilling resistance (N) | Undeteriorated | Mean | 18.82 | 15.50 | 19.11 | 16.14 | 17.03 | |
Standard deviation | 1.11 | 0.54 | 1.19 | 0.52 | 1.11 | |||
Deteriorated | Mean | 16.26 | 13.00 | 15.56 | 10.50 | 9.58 | ||
Standard deviation | 0.98 | 0.70 | 1.34 | 1.46 | 0.91 | |||
\(K\)(%) | Â | Â | 13.60 | 16.13 | 18.58 | 34.94 | 43.75 | |
