Large Scale Buckling Tests of Bar Bundle Columns

Abstract Bar bundle columns are a new type of composite column. For this purpose, a bundle of high-strength reinforcing bars with a yield strength of 670 N/mm2 is set in a steel tube and then grouted with mortar. Due to the lower cross-sectional thickness of the threaded bars, no strength reduction due to material thickness effects is required compared to a solid core cross-section. The bundling of the steel bars results in a high steel content in relation to the total cross-section; as a result, the novel composite column achieves load-bearing capacities that are usually typical for columns with significantly larger cross-sectional dimensions. In addition, bar bundle columns exhibit better heating behavior compared to composite columns with solid cross sections, as the bars only touch at certain points. As part of the AiF research project IGF- 20352 N, 10 buckling tests with lengths between 3.5 m and 8 m were carried out. Cross sections with 1, 3, 7 and 19 bars as core were investigated. The experimental setup, the measurement technique and the results are shown here.     «

Abstract Bar bundle columns are a new type of composite column. For this purpose, a bundle of high-strength reinforcing bars with a yield strength of 670 N/mm2 is set in a steel tube and then grouted with mortar. Due to the lower cross-sectional thickness of the threaded bars, no strength reduction due to material thickness effects is required compared to a solid core cross-section. The bundling of the steel bars results in a high steel content in relation to the total cross-section; as a resul...     »