Application of the substructure method to assess the fire resistance of thermally restrained columns
- Usually, the fire resistance of load-bearing structural elements is determined by single members testing. A mechanical load is applied to the member in a force-controlled manner and is maintained constant throughout the fire test. After applying the mechanical load, the thermal exposure starts according to the ISO 834 fire curve. In this conventional test method, no interaction between the tested member and the entire building structure is considered. In buildings, the surrounding structure can restrain the thermal expansion of a member in case of fire. This may have both positive and negative effects on the fire resistance of this structural element. Several years ago, the Institute for Sustainability and Innovation in Structural Engineering (ISISE) at the University of Coimbra in Portugal and the Bundesanstalt für Materialforschung und -prüfung (BAM) in Germany carried out fire tests on circular and square steel-reinforced concrete columns with restrained thermal expansion. BAM´sUsually, the fire resistance of load-bearing structural elements is determined by single members testing. A mechanical load is applied to the member in a force-controlled manner and is maintained constant throughout the fire test. After applying the mechanical load, the thermal exposure starts according to the ISO 834 fire curve. In this conventional test method, no interaction between the tested member and the entire building structure is considered. In buildings, the surrounding structure can restrain the thermal expansion of a member in case of fire. This may have both positive and negative effects on the fire resistance of this structural element. Several years ago, the Institute for Sustainability and Innovation in Structural Engineering (ISISE) at the University of Coimbra in Portugal and the Bundesanstalt für Materialforschung und -prüfung (BAM) in Germany carried out fire tests on circular and square steel-reinforced concrete columns with restrained thermal expansion. BAM´s column test furnace allows the specimen to be subjected to thermal exposure and mechanical loading simultaneously. In addition, this device has a substructure test module, which can also provide restrained test conditions. In an ongoing research project at BAM and Technische Universität Braunschweig, the effect of restrained test conditions on the behaviour of steel-reinforced columns under fire exposure is further investigated. The comprehensive test programme of the project includes 14 steel-reinforced concrete columns. Several parameters are varied, i.e., the stiffness representing the surrounding structure of the column, the load level, the eccentricity of the applied load, and the fire exposure to be used. The selection of parameters is based on a real building case study. Furthermore, material tests are carried out to characterize the mechanical properties of the concrete at elevated temperatures, to be included in a numerical simulation.…


| Autor*innen: | Tim NeugumORCiD |
|---|---|
| Koautor*innen: | Ludwig StelznerORCiD, Dustin HäßlerORCiD, Sascha HothanORCiD |
| Dokumenttyp: | Vortrag |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2026 |
| Organisationseinheit der BAM: | 7 Bauwerkssicherheit |
| 7 Bauwerkssicherheit / 7.3 Brandingenieurwesen | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurbau |
| Freie Schlagwörter: | Fire tests; Numerical simulation; Steel-reinforced concrete columns; Substructure method; Thermal constraint |
| Themenfelder/Aktivitätsfelder der BAM: | Infrastruktur |
| Infrastruktur / Fire Science | |
| Veranstaltung: | Vortrag an der Helmut-Schmidt-Universität der Bundeswehr in Hamburg |
| Veranstaltungsort: | Hamburg, Germany |
| Beginndatum der Veranstaltung: | 27.01.2026 |
| Enddatum der Veranstaltung: | 27.01.2026 |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 02.02.2026 |
| Referierte Publikation: | Nein |
| Eingeladener Vortrag (wissenschaftliche Konferenzen): | Nein |

