Issue 70

H. A. Mohamed et alii, Frattura ed Integrità Strutturale, 70 (2024) 286-309; DOI: 10.3221/IGF-ESIS.70.17

a- Load-displacement curves b- Backbone curve Figure 20. Experimental [20] vs. FEM lateral load – lateral displacement of RC column.

Figure 21. Details of RRC column.

Rubberized concrete columns' response at cyclic loading In this research, the behavior of the experimentally tested columns when exposed to cyclic loads was investigated numerically using the FEM for square reinforced concrete columns with identical geometry, material characteristics, and boundary conditions. A reference point at the top of the column was used to apply a constant vertical load. Following the application of the axial load in the first stage, a horizontal displacement was applied via a reference point attached to the column head as part of a displacement control technique in the second stage (see Fig. 23). Square columns measuring 1.5 meters in height were subjected to an axial force of 190 kN, while columns measuring 1.8 meters in height were exposed to an axial load of 178 kN. This axial load is estimated to be about 10% of the axial compressive capacity of the columns in both cases. The lateral displacement of all columns was carried out in accordance with the loading protocol illustrated in Fig. 19 and detailed in ACI 374 [21]. A perfect bond between concrete and steel was considered, and no slip was observed in the experimental tests and FE verification model; thus, the interaction between reinforcing steel bars/stirrups and concrete was simulated using embedded constraints. According to Section 4-2, the concrete damage plasticity (CDP) model was used to determine the material properties of the steel bars and concrete for these columns.

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