magistrsko delo
Jan Ratej (Author), Tomaž Hozjan (Mentor)

Abstract

V nalogi so predstavljene računske metode za določevanje požarne odpornosti križno lepljenih lesenih elementov. Analizirani sta dve metodi in sicer metoda, ki jo podaja standard EN 1995-1-2, ter metoda, ki je predstavljena v kanadskem priročniku CLT Handbook. Predstavljeni so tudi postopki numeričnega modeliranja križno lepljenih lesenih elementov in s pregledom stanja so podane tudi ugotovitve iz eksperimentalnih raziskav križno lepljenih plošč, ki so med drugim bile raziskane v naravnem merilu. Izkaže se, da sta pri določitvi požarne odpornosti skladno z metodo po EN 1995-1-2 najbolj vprašljivi določitev debeline nenosilnega sloja d0 in določitev debeline zoglenelega sloja dchar. Posredno težavo pri križno lepljeni ploščah predstavlja tudi delaminacija slojev in z njo povezano modeliranje oziroma upoštevanje v preprostih računskih postopkih, ki je zaenkrat dokaj nenatančno upoštevano. Težava je predvsem v določitvi kritične temperature, kdaj lepilo odpove in pride do delaminacije, ter pri določitvi povišane stopnje oglenenja lesa, do katere pride zaradi delaminacije sloja. Bistveni del naloge predstavlja zadnje poglavje, ki je namenjeno parametrični študiji določitve požarne odpornosti križno lepljene plošče skladno z EN 1995-1-2 in kanadskim priročnikom CLT Handbook. Analiziran je vpliv velikosti odprtin in požarnega sektorja na rezultate požarne odpornosti plošče za parametrično požarno krivuljo. Razvoj požara je določen skladno z EN 1991-1-2. Ugotovljeno je, da požar v izključno eni sobi ne predstavlja nevarnosti, v primeru, da bi se požar razširil po celotnem stanovanju, pa plošča požara ne bi prenesla. V zadnjem delu parametrične študije je prikazana razlika med metodama po EN 1995-1-2 in CLT Handbook za določitev standardne požarne odpornosti. Primerjava je narejena za križno lepljene plošče različnih debelin in slojevitosti plošč ter razponov. Glede na rezultate analiz je bilo ugotovljeno, da je metoda po kanadskem priročniku CLT Handbook praviloma bolj konzervativna.

Keywords

gradbeništvo;magistrska dela;požarna odpornost;križno lepljen les;numerično modeliranje;standardni požar;parametrični požar;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FGG - Faculty of Civil and Geodetic Engineering
Publisher: [J. Ratej]
UDC: 614.841.2:624.011.1(497.4)(043)
COBISS: 7837537 Link will open in a new window
Views: 2598
Downloads: 764
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Other data

Secondary language: English
Secondary title: Fire resistance of cross-laminated timber elements
Secondary abstract: Thesis discusses methods for determining fire resistance of cross-laminated timber elements. Two different methods are presented, one according to EN 1995-1-2 and one according to CLT Handbook. Procedures of numerical modelling of cross-laminated elements are presented as well. Based on reports of experimental analyses, where some of them were made in real scale, comments, corrections and findings are offered. It appears that when determining fire resistance according to standard EN 1995-1-2, zero-strength layer d0 and charring depth dchar are most questionable. Indirect difficulty with crosslaminated elements is delamination phenomenon, and with latter connected numerical modelling and integration of phenomenon in current calculation methods, that are still relatively inaccurate. Specific problem is the determination of the critical temperature at which the glue separates and therefore lamination occurs as well as determination of higher degree of charred wood that occurs due to delamination. The last chapter presents the essential part of the thesis. In this chapter, parametric study for determining fire resistances of CLT slab according to European EN 1995-1-2 and Canadian CLT Handbook is performed. Parametric study discusses the effects of different sizes of openings and size of fire compartment where development of parametric fire is determined according to EN 1991-1-2. It was found out that fire limited to solely one room does not cause failure of the CLT slab, but in the case if fire progresses to entire apartment, fire would cause failure of the CLT element. Last part of the parametric study discusses deviation between both methods for determining the standard fire resistance of CLT elements. In the study influence of varying number of layers and length of CLT plate is compared. Comparison showed that more conservative results are obtained with CLT Handbook method.
Secondary keywords: civil engineering;master of science thesis;fire resistance;cross-laminated timber;numerical analysis;standard fire curve;parametric fire curve;
File type: application/pdf
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Pages: XVI, 113 str.
ID: 9235972