PSI - Issue 44

Paolo Zampieri et al. / Procedia Structural Integrity 44 (2023) 926–933 Zampieri et al./ Structural Integrity Procedia 00 (2022) 000–000

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of the arch take place in the first cracking hinge at the left of the application load axis.. At the end of the test, the registered residual load corresponds to the 56% of the peak load and the damage configuration is showed in Fig. 6.

Fig. 6. Graphical representation of the damage observed during the test.

4.2. CFRCM strengthened arch (S1) The test performed on the strengthened arch highlighted a peak load of 54 kN. The collapse mechanism is similar to the un-strengthened arch. At the peak load the arch model exhibits 4 hinges meanwhile in the post-peak phase a shear/sliding collapse occurs similarly to the previous test. However, the test performed on the strengthened arch does not show a crack in the keystone (Fig. 6) and the closing of the hinge suited in the application load position (Fig. 5), unlike the un-reinforced one. The first damages and cracking are observable, when it was applied the cycles with an imposed displacement of 0.9 mm, in the interface between arch and haunching in the application load side. By increasing the displacement imposed and reaching the value of 1.5 mm, the arch shows the first crack of the reinforcement system, placed in the block 23/24 near the load axis. At the peak load, observed in the first cycle with 6mm of imposed displacement, the specimen exhibits a typical 4 hinges mechanism. The end of the test is due to the formation of the shear-sliding mechanism in the same position of the unstrengthened arch.