Thickness of zero-strength layer in timber beam exposed to fuel-controlled parametric fires

Huč, Sabina (avtor), Hozjan, Tomaž (avtor), Pečenko, Robert (avtor)

Fire resistance is one of the essential requirements to be fulfilled in the design of timber structures. For this purpose, a reduced cross-section method is given in the European standards, Eurocodes. The method is based on the assumption that an initial, rectangular timber cross-section exposed to fire conditions reduces to an effective cross-section, which has material properties as at a room temperature. The reduced part of the cross-section with no resistance is determined by a sum of two parameters, namely a charring depth and a thickness of zero-strength layer. Eurocodes give a value of the latter only for the standard fire exposure, which is only one of the fire curves proposed in the same standards. Therefore, the present paper examines the thickness of zero-strength layer in case of 46 different fuel-controlled parametric fire exposures applied to a timber beam from three sides. A four-phase numerical analysis is applied for this purpose that includes the use of a hygro-thermal model and a mechanical model to determine temperatures of timber over the cross-section and the mechanical resistance of timber beam in fire conditions, respectively. The results show that the thickness of zero-strength layer takes the values between 7.9 and 18.4 mm for the fuel-controlled parametric fire exposures. Since it is clearly dependent on the parameters describing the parametric fire curve, five equations are proposed that can be used for determination of the thickness of zero-strength layer in case of parametric fire exposures.

• Jezik: Angleški jezik
• Ključne besede: zero-strength layer, parametric fire, timber beam
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FGG - Fakulteta za gradbeništvo in geodezijo ; FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2023
• Št. strani: Str. 929-944
• Številčenje: Vol. 57, iss. 4
• PID: 20.500.12556/RUL-151732
• UDK: 624.011.1:624.072.2:614.84
• ISSN pri članku: 0043-7719
• DOI: 10.1007/s00226-023-01480-8
• COBISS.SI-ID: 160140291
• Datum objave v RUL: 18.10.2023

Gradivo je del revije

• Naslov: Wood science and technology
• Skrajšan naslov: Wood sci. technol.
• Založnik: Springer Nature, International Academy of Wood Science
• ISSN: 0043-7719
• COBISS.SI-ID: 9151749

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: debelina nenosilnega sloja, parametrični požar, leseni nosilec

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: N2-0183
• Naslov: Stohastični model oglenenja lesa v pogojih naravnega požara

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P2-0260
• Naslov: Mehanika konstrukcij