EVALUATION ON THE BEHAVIOUR OF STEEL-CONCRETE COMPOSITE COLUMN AND REINFORCED CONCRETE BEAM JOINT UNDER STATIC CYCLIC LOADING

• Main Author: (NIM 250 04 040), Iskandar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8285
• Institution: Institut Teknologi Bandung

Abstract : <br /> <br /> <br /> This research is aimed at understanding the behaviour of steel-concrete column and steel-framed concrete beam joint under static cyclic loading. The research consists of experimental research and numerical analysis with non-linear finite element method. Experimental research is conducted towards 3 specimens of external column beam joint with planned compressive concrete strength of 30 MPa. The first specimen (BU-1) is in the form of conventional beam-column joint, the second specimen (BU-2) uses composite column with reinforcement of beam extending the column, and the third specimen (BU-3) also uses composite column, but the reinforcement of beam is welded into the column steel casing. The first test item (BU-1) is used as a reference to the other specimens. <br /> <br /> <br /> The results of experimental research with cyclic loading were crack pattern, hysteretic curve of relation between load and deflection, energy dissipation, steel strain, strength degradation, and stiffness degradation at each loading cycle. failure. In every compressive repeated cyclic loading, there is a slip on the low load, namely pinching effect. Due to pinching effect, strength degradation, stiffness degradation, and energy dissipation degradation took place. Results obtained showed that BU-1 behaviour was similar to BU-2, especially in the ability of energy dissipation, crack pattern, strength and stiffness produced. While the behaviour of BU-3 was very different with BU-1 Crack taking place at plastic hinge area at BU- 1 and BU-2 was dominated by flexural crack, thus collapse taking place was ductile flexural collapse. While at BU-3, the behaviour was dominated by shear deformation, so that a mechanism was formed, in which a large displacement took place at low load, and crack taking place at the column was very little. <br /> <br /> <br /> To determine the stress distribution at specimen of beam-column joint, a numerical analysis was necessary since the experimental result was not able to represent stress distribution character. The numerical analysis in this study uses non-liner discrete finite element method. Then, the result of numerical analysis was verified towards experimental study result. The result obtained showed that energy dissipation as well as stiffness as a result of numerical analysis result was a little higher than experimental result. Based on the contour of concrete compression stress distribution, at elastic condition, the compression stress concentration was more dominant at the beam, either due to tension load or compression load. Then, with the increase of ductility, in which the load given was higher, the stress concentration become higher, either at the beam or column, this was marked by the forming of compression stress strut which become wider at the column. The behaviour is true only for specimen BU-1 and BU-2. However, the last specimen behaves differently as for this specimen the shear deformation is dominated. The diagonal strut action is slightly developed showing that the slip occurs at the face of the column significantly. Therefore, the specimen BU-3 behaves very poor as compared to the other ones. <br /> <br /> <br /> The behaviour of each specimen from numerical analysis result if compared to experimental result in general is almost the same, especially at the relation of load deflection, energy dissipation, as well as strength and stiffness degradation. Therefore, it may be concluded that the numerical analysis result may be used as test model of experimental result.