Effect of Air-gap on Response of Fabricated Slim Floor Beams in Fire

[en] Fabricated slim floor beams are a type of shallow floor systems which are formed by welding a steel plate to the bottom flange of an I-shaped steel section. The welded steel plate adds asymmetry to the steel section and improves its structural response by efficient utilization of the material strength. During their fabrication process, an air-gap is induced between the steel plate and the bottom flange, which, at elevated temperatures, acts as a layer of insulation and influences the temperature development across their section. Due to the presence of this air-gap, temperatures on the bottom flange remain lower in fire conditions, hence, these beams offer an improved fire resistance in comparison to other similar beam types. This study addresses the thermal and structural response of fabricated slim floor beams at elevated temperatures and investigates the influence of the air-gap. Finite element modelling is performed to analyse the response of these beams in fire and the predicted behaviour is validated by replicating the experimental data from the literature. The elaborated finite element modelling method is then employed to conduct sensitivity studies to investigate the effect of the presence and size of the air-gap on their thermal and structural response at elevated temperatures. Results from the studies demonstrate that the presence of the air-gap has a considerable influence on their thermal behaviour, however, the size of the air-gap has no or negligible effect on their thermal behaviour. The structural analyses show that the presence of the air-gap has a significant influence on the structural response of fabricated slim floor beams at elevated temperatures. The size of the air-gap, however, has no significant influence on their structural response in fire. As the presence of air-gap is helpful and beneficial, the findings of this research can be used to develop similar designs for structural members as an efficient and inexpensive way to improve their thermal behaviour and structural response in fire.

Disciplines :

Civil engineering

Author, co-author :

Alam, Naveed

Nadjai, Ali

Maraveas, Chrysanthos ; Université de Liège - ULiège > Département ArGEnCo > Ingénierie du feu

Tsavdaridis, Konstantinos

Language :

English

Title :

Effect of Air-gap on Response of Fabricated Slim Floor Beams in Fire

Publication date :

2018

Journal title :

Journal of Structural Fire Engineering

ISSN :

2040-2317

Publisher :

Emerald Group Publishing, United Kingdom

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBi :

since 11 September 2018

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