COMPARASION FIRE RESISTANCE BEAM LOADED IN BENDING OF TWO DIFFERENT MATERIALS

Požar kao izvanredno djelovanje predstavlja djelovanje za koje se pretpostavlja da se neće dogoditi u znatnoj veličini u tijeku eksploatacije objekta. Postoje različiti pristupi proračunu požarne otpornosti gdje su neki od pristupa primijenjeni u ovom diplomskom radu. Cilj diplomskog rada je usporedba požarne otpornosti proste grede opterećene na savijanje od dva različita materijala. Za usporedbu se koristi lijepljeno lamelirano drvo - GL 24h te čelik klase S275. Požarna otpornost drvene grede na savijanje provedena je prema važećim HRN EN 1995-1-2 normama te je korištena metoda smanjenja poprečnog presjeka. Požarna otpornost čelične grede može se provesti na tri načina: u funkciji vremena, čvrstoće i temperature. Požarna otpornost čelične grede na savijanje provedena je prema važećim HRN EN 1993-1-2 normama te je korišten proračun požarne otpornosti u funkciji vremena. Radom je obuhvaćen proračun požarne otpornosti nezaštićene drvene grede, proračun požarne otpornosti nezaštićene čelične grede te proračun požarne otpornosti zaštićene čelične grede kako bi se mogla napraviti relevantna usporedba.Fire as an extraordinary effect is an act that is assumed to not occur in significant size during the exploitation of the object. There are different design approaches to the fire resistance calculation where some of the approaches applied in this graduate work. The aim of the graduate work is to compare the fire resistance of the common beam loaded to the bending of two different materials. For comparison were used the glued laminated timber - GL 24h and the steel class S275. The bending resistance of the timber beam was carried out in accordance with the current HRN EN 1995-1-2 norms and a cross sectional reduction method was used. The fire resistance of steel beam can be carried out in three ways: in function of time, strength and temperature. The fire resistance of the steel beam on bending was carried out according to the current HRN EN 1993-1-2 norms and the calculation of fire resistance was used in function of time. The work covered the calculation of the fire resistance of unprotected timber beam, the calculation of fire resistance of unprotected steel beam and the calculation of fire resistance of the protected steel beam so that a relevant comparison could be made