P 12 - Stiffenerless steel frame structures and thin-walled solid wall beams, calculation and design

P 08.1-2 - Fire behaviour of concrete-filled hollow steel sections and open steel sections with concrete encasement The aim of the present work was to record and evaluate fire tests carried out to date on concrete-filled hollow steel sections and open steel sections with concrete encasement and to draw up a test programme based on the results to date. During the research carried out - particularly in Germany and France - it was established that specific tests have only been carried out recently on hollow steel sections filled with concrete; tests on open steel sections with concrete encasement, on the other hand, were carried out more than 25 years ago, i.e. the status of the latter constructions is virtually unchanged compared with [1]. The recording and evaluation of existing fire test results therefore only covered hollow steel sections. Results from Germany (Federal Institute for Materials Testing (BAM), Berlin), France (Centre Scientifique et Technique du BAtiment (CSTB), Paris, and Centre Technique Industriel de la Construction Metallique (CTICM), Metz) and Great Britain (Fire Research Station (FRS), Boreham Wood) were used for this purpose. The publication [1] served as the source for the German test data. The results of the tests carried out in Great Britain and some of the tests carried out in France were taken from correspondence provided by the Studiengesellschaft für Anwendungstechnik von Eisen und Stahl e.V. (Study Association for Application Technology of Iron and Steel). The latter information is incomplete and is essentially limited to the tested profiles, their load and the fire resistance duration achieved. Other important details such as the quality of the steel and concrete and the knee lengths of the tested columns are only available in isolated cases. In particular, the above-mentioned sources lack temperature data. The test data taken from the correspondence can therefore only be analysed to a limited extent. The tests carried out in France in more recent times - which represent the majority of the tests recorded - are available in the form of standardised short reports from COMTUBE, the client of the above-mentioned investigations. These reports contain the most important data, but no information on the temperature-time curve of the test specimens. Complete test certificates from the CSTB are available for a few fire tests. Efforts to obtain complete test certificates from COMTUBE for all recent tests carried out in France were unfortunately unsuccessful. As already mentioned, most of the data collected is based on fire tests carried out in France. After an initial review and preliminary evaluation of the available results, the author undertook an information trip to the CSTB in Paris and CTICM in Metz in order to complete the collected data and to clarify open questions - in particular with regard to the static and thermal test conditions. Finally, it should be noted that the fire tests on concrete-filled hollow steel sections carried out on behalf of COMTUBE in France are continuing, so that further information can be expected in the form of the above-mentioned short reports. The present report is based on the status of September 1975 (last recorded test on 11 September 1975 at the CSTB). Publication: 1975 Authors: Prof. Dr.-Ing. K. Roik, Dipl.-Ing. R. Bergmann, Dr.-Ing. H. Bode, G. Wagenknecht

P 08.1 - Load-bearing behaviour of steel columns in combination with concrete (hollow sections) This paper contains the calculation and design of concrete-lined hollow section columns made of structural steel under compression and uniaxial bending. After a brief introduction, Section 2 summarises international research work in this field. In Section 3, a calculation programme is developed as an accurate numerical method. Section 4 contains interaction relations for the ultimate limit state for the whole range between centric compression and pure bending. Many results obtained with the described calculation programme and the interaction curves are compared with each other and with available test results; very good agreement can almost always be observed. Publication: 1975 Authors: Prof. Dr.-Ing. Roik, R. Bergmann, H. Bode, G. Wagenknecht

P 08.2 - Load-bearing behaviour of steel columns in combination with concrete (open profiles) This paper contains the calculation and design of steel columns in concrete under compression and uniaxial bending. Some comments and design suggestions are also made for biaxial bending. Section 2 summarises international research work. Section 3 explains a calculation programme that is used for precise numerical calculation. Section 4 contains interaction relations and design proposals based on the European buckling stress curves. The proposed design procedure is explained using a number of examples. Numerous ultimate loads determined in accordance with Sections 3 and 4 are compared with foreign test results. A generally good agreement can be established Publication: 1976 Authors: J. Stanke