Table 6 Results of pull out tests
From: Improving Bond Performance of Near-Surface Mounted Steel Ribbed and Threated Rods in the Concrete
Specimen ID | τu (Mpa) | Gain in τu (%) | δu (mm) | Gain in δu (%) | Stiffness k (MPa/mm) | Gain in k (%) | Toughness T (MPa.mm) | Gain in T (%) |
|---|---|---|---|---|---|---|---|---|
Bonded length impact of ribbed rods embedded in substrate concrete; group A | ||||||||
R7ØN | 13.5 | 0.00 | 1.01 | 0.00 | 60.05 | 0.00 | 13.00 | 0.00 |
R10ØN | 10.5 | − 22.22 | 0.9 | − 10.89 | 23.10 | − 61.53 | 4.73 | − 63.65 |
R15ØN | 9.1 | − 32.59 | 0.49 | − 51.49 | 22.50 | − 62.53 | 2.23 | − 82.85 |
Bonded length impact of NSM ribbed rods; group B | ||||||||
R7ØE | 15 | 0.00 | 3.02 | 0.00 | 5.90 | 0.00 | 22.65 | 0.00 |
R10ØE | 12.6 | − 16.00 | 2.65 | − 12.25 | 6.80 | 15.25 | 16.70 | − 26.29 |
R15ØE | 11.9 | − 20.67 | 15.71 | 420.20 | 5.40 | − 8.47 | 115.00 | 407.73 |
Filling epoxy/surface pattern impact of NSM rods; group C | ||||||||
R7ØN | 13.5 | 0.00 | 1.01 | 0.00 | 60.05 | 0.00 | 13.00 | 0.00 |
R7ØE | 15 | 11.11 | 3.02 | 199.01 | 5.90 | − 90.17 | 22.50 | 73.08 |
S7ØE | 16.5 | 10* | 3.11 | 2.98* | 10.10 | 71.2* | 25.70 | 14.22* |
Bonded length impact of NSM threaded rods; group D | ||||||||
S0 = S5ØE | 18.9 | 0.00 | 1.35 | 0.00 | 24.30 | 0.00 | 12.76 | 0.00 |
S7ØE | 16.5 | − 12.70 | 3.11 | 56.60 | 10.10 | − 58.40 | 25.66 | 101 |
End nuts impact of NSM threaded rods; group E | ||||||||
S0 | 18.9 | 0.00 | 1.35 | 0.00 | 24.30 | 0.00 | 12.76 | 0.00 |
S-1n5 | 20.4 | 7.94 | 3.5 | 159.26 | 6.10 | − 74.90 | 35.70 | 179.78 |
S-2n5 | 21.17 | 12.01 | 3 | 122.22 | 9.50 | − 60.91 | 31.76 | 148.86 |
S-1n10 | 22.1 | 16.93 | 2.6 | 92.59 | 9.55 | − 60.70 | 28.73 | 125.16 |
End rings impact of NSM threaded rods; group F | ||||||||
S0 | 18.9 | 0.00 | 1.35 | 0.00 | 24.30 | 0.00 | 12.76 | 0.00 |
S-1r | 19.8 | 4.76 | 2.95 | 118.52 | 9.50 | − 60.91 | 29.21 | 128.92 |
S-2r | 20.6 | 8.99 | 2.5 | 85.19 | 24.20 | − 0.41 | 25.75 | 101.84 |
S-3r | 21.55 | 14.02 | 1.63 | 20.74 | 15.40 | − 36.63 | 17.56 | 37.67 |
Longitudinal bars impact of NSM threaded rods; group G | ||||||||
S0 | 18.9 | 0.00 | 1.35 | 0.00 | 24.30 | 0.00 | 12.76 | 0.00 |
S-2b | 20.2 | 6.88 | 3.6 | 166.67 | 17.20 | − 29.22 | 36.36 | 185.01 |
S-3b | 21.17 | 12.01 | 3.21 | 137.78 | 18.10 | − 25.51 | 33.98 | 166.34 |
S-4b | 22.49 | 18.99 | 2.14 | 58.52 | 17.90 | − 26.34 | 24.06 | 88.63 |
Spiral bars impact of NSM threaded rods; group H | ||||||||
S0 | 18.9 | 0.00 | 1.35 | 0.00 | 24.30 | 0.00 | 12.76 | 0.00 |
S-1 s | 20.98 | 11.01 | 1.52 | 12.59 | 25.50 | 4.94 | 15.94 | 24.98 |
S-2 s | 21.9 | 15.87 | 1.4 | 3.70 | 26.10 | 7.41 | 15.33 | 20.16 |
S-3 s | 23.8 | 25.93 | 1.33 | − 1.48 | 26.40 | 8.64 | 15.83 | 24.06 |