Experiments on steel columns under fire conditions

Abstract

Material and structural stability behaviour at elevated temperatures are key considerations for structural fire safety. This report describes experimental results of material coupon as well as structural stub and slender column furnace tests on carbon steel specimens at elevated temperatures. The tests were executed at the Technical University of Darmstadt, Germany, and at the ETH Zurich, Switzerland. The report is organized into eight chapters. After the introduction chapters 2 to 4 describe the test programme and the preparatory measurements of the geometry and initial geometrical imperfections of the stub and slender column test specimens. Steady state stub and slender column tests were executed at ambient and elevated temperatures (400 °C, 550 °C and 700°C) on four different box sections (SHS 100·100·4, SHS 160·160·5, SHS 200·200·5 and RHS 120·60·3.6) and one H-section (HEA 100). Transient state slender column tests were executed on HEA 100 test specimens. The compressive load was applied centrically or eccentrically to the stub and slender column test specimens. Chapter 5 contains information on the experimental investigation of the material behaviour of the column tests. The chapter gives the testing programme, the geometry of the test specimens, the test setups and the test results of all material coupon tests. Thereafter chapters 6 to 8 contain detailed descriptions about the test setup, the execution and the results of the stub and slender column tests. Extensive appendices are given at the end of the report. Appendix A contains all the measured geometrical values of each column test specimen. In addition the resulting cross-sectional area and the moments of inertia about both the strong and the weak axis of each specimen are given. Appendix B contains the measured initial local geometrical imperfections of each face of each stub column test specimen and the measured initial global geometrical imperfections of each face of each slender column test specimen. Appendix C contains information of the material coupon tests. All measured geometrical values of each test specimen are given. The conditions of each test are summarised and the resulting stress-strain relationship of each tensile or compressive material coupon test are given. Material parameters resulting from each test are also summarised. Appendix D contains the stub and slender column test results. For each test specimen the test conditions (including the boundary conditions and the load application) are indicated and the ultimate load and the vertical and horizontal deformations at ultimate load are given for each test. In addition, different graphs show the temperature, the vertical deformation and the mechanical load during each test, as well as a load-displacement curve.