Saturday, October 19, 2019
Structural Fires and Structural Failures Essay Example | Topics and Well Written Essays - 1750 words
Structural Fires and Structural Failures - Essay Example Efforts started in 1980 to keep track of fires and take measures to reduce structural failures and after three decades, the damages in casualties as well as property reduced by almost fifty percent. Structures were classified into different types to better access the parameters and predict the time the fire takes to consume the structure. This classification also gives firefighters better assessment to fight or counter fires. The speed by which fires spread throughout the structure depends on three major factors; oxygen source, fuel and the heat source. Oxygen is necessary for burning and air is the primary source, the interior of the structure provides fuel source for burning and different components burn with different speeds, and finally; some elements of the structure contribute towards the heat source which raises the air temperature to a point where everything bursts into flame and it is known as flashover. Structural fires reaching flash point are almost impossible to control and often lead to structural failure. Structure Types Structural fires are classified as per type of structures, depending on their external and internal composition of construction materials. Since every material burns with a different rate and in turn produces heat as well as smoke. Heat released contributes towards raising temperature of local air, which results in flash over. Every structure has different set of materials and that is why each structure takes different time to reach flash over. The structures are classified into five types with ascending rates of burning. Type I consists of structures with steel and concrete used to provide structural strength, making it the most resistant to fires. Type II uses steel to reinforce the structure of the roof, which provides additional support for the structure and in particular delays roof collapse. Type III is ordinary structures with exterior and interior made of brick and mortar, which are non-combustible. The interior may also have laminated or fire retardant wooden floors. Type IV is heavy timber structures which rely on timber to reinforce the structure, however, the exterior walls are made from bricks. Type V are wooden structures with wood used to form the basic frame of the structure, as well as, exterior and interior (Dunn, 2013). In simple, structures with steel and concrete, that is Type I and II, are the most resistant to fire as they are capable of handling heat generated for longer durations, whereas, structures with wood, either interior or exterior are destroyed at a faster rate, which includes Type IV and V. Occupancy Types Occupancy type involves type of activity the structure is designed for and therefore, classified accordingly for fire hazards. Structural fires are a result of human actions and the type of occupancy dictate regulations for a specific structure. Some of the groups among this classification include Assembly, Business, Education and Factories. These groups are subdivided de pending on type of activities carried out within the structure. In general, fire hazard increase with increase in the number of occupants within the structure as well as the scope of activity. Factories are more susceptible to fires than any other group, because, they involve manufacturing and storage. The materials involved are much more hazardous and chances of fires are much
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