Experimental and Numerical Analysis of Concrete Columns under Axial Load Based on European Design Norms

Abstract

This study presents a comparison between numerical and experimental results for reinforced concrete columns subjected to axial compression. Depending on the columns support and their organization within the structure, columns primarily work under either concentric or eccentric compression, respectively, bending in situations where horizontal actions such as wind or/and earthquakes are present in the structure. Different countries have specific design codes, and in this study, the calculation of columns is based on the European design codes, specifically EN 1992-1-1. As a common practice in most cases during research, tests are conducted using computational models, and based on the obtained results through the application of similarity theory, an attempt is made to transition to the actual behavior of structural elements. Therefore, this paper applies a logic of "almost real" testing, where two columns with square cross-sections were produced and tested. The columns had a rectangular base with cross-section dimensions of 20/20 cm and a height (L) of 300 cm, with a concrete strength of fcm,cube=61.80 MPa. They were reinforced with longitudinal reinforcement (4Ø12 mm) and had a tensile strength of ftm=588.10 MPa. Additionally, stirrups of Ø8 mm were placed at every sw=25 cm. Experimental results show a closer alignment with software calculations using SEISMOSOFT with an accuracy of 96%, while results according to EN 1992-1-1, based on simplified methods, show 64% for the Nominal Stiffness Method and 59% for the Curvature Method. Doi: 10.28991/CEJ-2024-010-02-05 Full Text: PDF

Experimental and Numerical Research on the Behavior of Steel Columns with Circular Hollow Cross Sections

“…For precise examination and reliable results, they were requested from the laboratory of "ProIng", Pristina, in order to calibrate the examination machine-piston, as shown in Figure 7. Calibration of the hydraulic piston was conducted using the "HBM Quantum X" equipment, ensuring the validated force of pressure fell within an accuracy range of +/-0.50 kN [4].…”

“…The behavior monitoring of the column, the obtained results from the experimental computation, calibration of the equipment's, testing of the proper technical installation of the fixed unit, direction of the installation of the strain gauges, etc., the applied load on the samples is static and shall be in increments as shown in Figure 10, the incremental diagram of the applied load. All measurements during the examinations are taken digitally via LVDT and Strain Gauge on equipment from "HBM Quantum X" [4,[20][21][22][23] The obtained results are based on the value of the young modulus of steel, Es=200000 N/mm 2 , in compliance with EN 199-1-1 [1,24]. The stress computation value on the basis of the strain (Hook-e Law) for the cross section of the column in the middle of the spam due to pressure contains:…”

“…Designing steel columns involves analyzing local and global stability, taking into account imperfection phenomena. This phenomenon has been meticulously addressed by a group of authors within the scope of the referenced work [4][5][6][7]. Currently, there are many studies available on section number [8], but the research on building up steel sections is comparatively limited.…”