Challenge Journal of Structural Mechanics
Yazarlar: Burak Kaan Cirpici
Konular:-
Anahtar Kelimeler:Unprotected steel,Protected steel,Passive fire protection system,Fire design,Industrial steel structure
Özet: In order to design a fire-resistant steel structure, the change in the physical and mechanical properties of the steel at high temperatures must be known. As the temperature of steel structural elements increases during fire, their strength decreases considerably. After a certain temperature, these strength drops reach critical levels. Therefore, collapses and various deformations (buckling, arching, etc.) occur. To prevent these collapses during the fire, various fire protection materials must be applied to the structural members such as column and beam. Columns are the most critical structural elements in a steel bearing system. While the possible collapse of the columns may cause the collapse of the whole structure, the beams alone may not cause the collapse of the structure, and the column-beam junctions directly affect the spread of fire. Since there will be many openings and gaps in industrial buildings, the spread and growth of a possible fire becomes very serious. Special fire protection measures are therefore required. In this study, the behavior of a steel industrial structure designed and designed under the influence of Standard Fire (ISO 834) was investigated, the distribution of the temperatures in the structural elements was determined, the required fire protection material was selected, and both protected and unprotected steel temperatures were determined. This design against fire is designed to provide fire resistance for 1 hour (60 min) for this structure. During this period, the type and optimum thickness of the protection material to be applied before reaching the critical temperature values for which the strength of the steel material would lose and would be damaged and compared with the temperatures that would occur in the structural elements without applying fire protection. According to the findings of the study, it was concluded that 25 mm drywall box protection material should be applied on the inner columns and 20 mm on the edge columns and 15 mm on the corner columns. In addition to this, it was concluded that spray beams (intumescent coating) of different thicknesses between 15-20 mm were applied to the beams depending on the location and the load to be affected and the type of joint. After these applied passive fire protection materials, the temperatures obtained in the structural elements reached to 500-550 as a result of 1-hour fire design. These temperatures are acceptable temperature values given the strength drop in critical temperature ranges for steel under the 1-hour fire condition.