PSI - Issue 10

N. Nikoloutsopoulos et al. / Procedia Structural Integrity 10 (2018) 141–147 N. Nikoloutsopoulos et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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(a) (b) Fig. 2. (a) Strengthening technique A.3 before and after the bending test; (b) Strengthening technique B.2 before and after the bending test.

(a)

(b)

Fig. 3. (a) Strengthening technique E.1.b before and after the bending test; (b) Strengthening technique F.1 before and after the bending test.

Ι t should be noted that Eurocode 8 (EN 1998-1, EC8) was used for the calculation of the theoretical results in strengthening techniques with strips and jackets (A, B, C), while for the calculation of the theoretical results in strengthening with rope techniques (D, E, F) the Technical Report No. 55 (TR-55) was used. The experimental out come of strengthening contribution is the value of the applied load at which the first shear crack appeared. Fig.4 shows the theoretical and experimental strength results of all strengthening techniques with strips. As it can be seen, for all techniques the theoretical strength results are below the required shear strength limit, with the exception of A.2. Strengthening technique C.2 exceeds the requirement only at experimental result. Fig.5 shows the theoretical and experimental strength results of all strengthening techniques with jacket. As it can be seen, the contribution of all techniques exceeds the required shear strengthen force of 30.2 kN. However, it is observed that the theoretical results of B.3 and C.3 are significantly lower than the experimental results. This is due to the constraint of EC8, which is given in next Eq.(1) and taken into account at theoretical calculations: σ fed ≤ 0.004·E f (1)