A model proposal concerning the determination of fire resistance ratings according to characteristics of closed spaces

In case of fire, buildings are required to remain standing during the period necessary for safe evacuation and for proper functioning of fire brigade crew. This is called structural fire resistance design. These periods in question are determined based on either performance or prescriptive rules. In the National Fire Protection Regulation grounded on prescriptive approach, envisaged fire resistance ratings for the design of constructional components and building are specified as prescriptive rules. These ratings are standard fire resistance ratings determined by standard fire curves. However, constructional components cannot resist to severe fire that take place in closed spaces composing the building through envisaged periods. As a result of this, the building may collapse sooner than the envisaged periods set out in the National Fire Protection Regulation. By this study, a model concerning the determination of fire resistance rating according to characteristics of closed spaces is proposed. Model is aimed to be applied to office buildings, institutional buildings, residential buildings and buildings for accommodation purposes. Characteristics of closed space in this model are limited with floor area, opening area, ratio of opening area to floor area, location and size of opening, fire load density and building type. Model is applied to a sample hospital having various spaces with different intended uses. By using this model, consideration of closed spaces characteristics for determination of fire resistance ratings according to the National Fire Protection Regulation and for separating building into compartments has been ensured.