PSI - Issue 44

Samuel Barattucci et al. / Procedia Structural Integrity 44 (2023) 426–433 Barattucci et al./ Structural Integrity Procedia 00 (2022) 000–000

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(a) (b) Fig. 1. Tested masonry infilled r.c. frame: (a) geometry; (b) scheme of the r.c. frame reinforcement

longitudinal rebars of columns is equal to the maximum between 0.006 times the minimum required concrete area of column cross sections and 0.003 times the actual cross section area of concrete of the column. The characteristic compressive cubic strength R ck for concrete is equal to 20 MPa (corresponding to the cylinder strength f ck equal to 16.6 MPa for strength class C16/20), which is common in r.c. buildings of that time. Rebars made of steel grade Feb38K with a characteristic yield stress f yk = 375 MPa are used for reinforcement. The values of the allowable stresses are 7.40 MPa and 215 MPa for concrete and steel reinforcement, respectively. Furthermore, existing structures are generally endowed with infill panels, whose presence and mechanical properties increase significantly the lateral strength and stiffness of the building and influence the dissipative capacity and collapse mechanism of the structure. To take into account of this aspect, the r.c. frame has been endowed with infill panel with thickness equal to 12 cm. 3. Experimental testing of the infilled frame In this section the full-scale experimental test conducted at CIRI-EC laboratory of university of Bologna on the infilled r.c. frame is described. The experimental setup is described and test results are presented in terms of force displacement curve and observed failure modes. 3.1. Specimen description The specimen tested was the one-storey masonry infilled r.c. frame represented in Figure 1. The r.c. bare frame was casted using a C20/25 concrete class with a consistency class S4. The bare r.c. frame was infilled with a 12 cm thick masonry panel. The masonry infill was realized using extruded hollow blocks, placed with the holes in horizontal direction and assembled with pre-dosed mortar containing selected aggregates, hydrated lime, hydraulic binder, eminently hydraulic lime and specific additives. Reinforcement of columns and top beams of the r.c. frame was realized according to the design reported in Section 2 and are depicted in detail in Figure 1b. The reinforcement of the base beam was specifically designed to provide adequate anchoring of the fixing steel plates used to fasten the r.c. frame to the strong floor.