PSI - Issue 78

Francesca Mattei et al. / Procedia Structural Integrity 78 (2026) 2169–2175

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The typical reinforcement layout consisted of horizontal rebars 2 ϕ 6/20 connected at the ends to steel plates measuring 70 × 70 × 6 mm, and vertical rebars ϕ 10/25 continuous up to the top RC beam, where appropriate anchorage was provided. Hook rebars ϕ 10/25, overlapping the vertical bars by approximately 70 cm, were used to connect the panel to the foundation. The foundation incorporated longitudinal bars ϕ 16 and stirrups spaced at ϕ 10/10 cm in the middle section and ϕ 10/5 cm at the end sections. Before casting, holes were drilled in the foundation to allow connection to the laboratory strong floor. The RC top beam, centred with the RC layer, was reinforced with longitudinal bars 3 ϕ 16 (top and bottom) and stirrups ϕ 8/25. Holes were made in the concrete casting, spaced at 375 mm, to enable connection to the loading system. Concrete class C25/30 was used.

Test setup and instrumentation

A horizontal monotonic test was performed. Both the masonry wall and the retrofit wall were subjected to a vertical load simulating the weight of an upper wall of similar dimensions, replicating the conditions of a two-storey building ( Fig. 2 ). Horizontal displacements were applied in a quasi-static way, avoiding significant dynamic effects — using hydraulic jacks anchored to the steel contrast frame of the University of Pisa laboratory. The uniform redistribution of the load, applied at the top RC beam, was ensured by a rigid steel transverse beam.

Fig. 2. Example of the scheme of the test setup.

The complete test setup consisted of: (a) a vertical load application system, (b) a horizontal displacement/load transfer system, and (c) supporting steel structures to prevent out-of-plane mechanisms, facilitate assembly, and ensure control over the test execution. Horizontal displacements were applied through two hydraulic jacks (for each one, stroke ±250 mm and load capacity of 400 kN) connected, on one side, to the steel contrast wall of the laboratory and,