Determination on Fire Resistance Composite Beams in the Fire Sector

Zejneli, Shinasi (2020) Determination on Fire Resistance Composite Beams in the Fire Sector. Journal of Applied Sciences-SUT JAS-SUT, 6 (11-12). pp. 128-142. ISSN 2671-3047

Text (Determination on Fire Resistance Composite Beams in the Fire Sector) 12.pdf - Published Version Download (1MB)

Abstract

Aim: Unwanted fire is a destructive force that causes thousands of deaths and severe property damage each year. The fire is a spontaneous process of uncontrolled burning with negative effects expressed through the destruction of material goods and endangering human lives. Many of the artificial fires were caused by wars, other weather disasters, lightning, but as well as the poor construction techniques used in the construction of buildings with highly flammable materials. The main factor that motivates us is to design a construction that will have high fire safety with which there will be no great economic and human loss due to its premature collapse. Method: Analysis of fire resistance of construction structures according to technical regulations: The action of high temperature on the interlocking structures causes a decrease in the mechanical properties of the two composite components (concrete and steel), and thus drastically reduces their load capacity, then they cause great damage and breakage. The design of fire resistance of construction structures is based on a certain fire scenario. Here are some of the types of fire scenarios that are applied worldwide. In most European countries, a standard fire-time curve is used according to ISO 834 and a parametric curve, the standard curve is very close to the time-temperature curve used in the United States, ASTM E119. (American Society for Testing and Materials). The constructive behavior of the composite elements in multi-storey buildings exposed to elevated temperature according to Eurocode 4, part 2. For the composite beams, the procedure for checking: - the bearing capacity of the cross-sections of bending, - vertical shear, -the load-bearing capacity of the longitudinal shear, - the bearing capacity of combined bending and vertical shear. Composite beams are considered, partially and completely concreted, as freely supported, or continuous beams. Nowadays, several software packages determine the fire resistance of load-bearing elements of a composite structure. One of the most widely used software packages in most European countries is ArcelorMittal, which has been used in the analysis of fire resistance of structural elements of a multi-storey building. Results: The fire resistance of the beams is calculated for three cases/ three types of beams with a span of L = 9.6 m/ - as an unprotected beam only of steel profile; - protected by gypsum board coating (d = 12.5mm); - partially concreted. Fire resistance analysis of composite beams The room temperature is taken as the initial temperature, and the heating is done gradually according to the standard temperature-time curve (ISO 834) with steps 20°С, 100°С, 500°С, etc., until complete cross-sectional plasticization (beam demolition). For the unprotected beam, a low class of fire resistance of R 30 was obtained, while for the other two cases the required fire resistance for such objects of R 120 was obtained. Conclusion: The unprotected beam • In the fire department for the burned steel beam, the following can be concluded: • -the critical temperature of the beam collapse is q cr = 805°C • -The fire resistance of the beam is Rpres = 33.95min • - the class of fire resistance of the beam is: R 30, which is less than that provided for this type of elements Rmin120 Protected composite beam with gypsum boards - d = 12.5 mm -the critical temperature of the beam collapse is q cr = 783°C -the fire resistance of the beam is R 120min and is equal to the one provided for this type of element. The partially concreted joint beam is performed according to the rules provided by Eurocode 4 for welded steel and concrete structures (Part 4). In the fire calculation, the standard temperature-time curve is used as in the previous elements. • For this type of beams, the program directly determines the class of fire resistance which in this case is equal to the predicted class R 120

Item Type:	Article
Uncontrolled Keywords:	composite constructions, composite inter-floor constructions, fire resistance, steel profile
Subjects:	A General Works > AI Indexes (General)
Divisions:	Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User:	Unnamed user with email zshi@unite.edu.mk
Date Deposited:	18 Nov 2020 10:09
Last Modified:	03 Dec 2020 11:01
URI:	http://eprints.unite.edu.mk/id/eprint/630

Actions (login required)

View Item