A Risk Based Framework for Time Equivalence and Fire Resistance

Periods of fire resistance are pervasive in the field of fire engineering. They are the basis of prescriptive structural fire guidance and also the end result of some quantitative analyses. Time equivalence methods are one such calculation approach that is used to define periods of fire resistance. However, these calculations often do not inherently consider the fundamental design challenges. These challenges are the fire safety goals and the constraints of the building and the physical world. The appropriate balance of these challenges is a solution. This paper further defines these concepts and gives examples of their application in the context of time equivalence analysis. It is found that the existing time equivalence methods do not adequately consider the challenges. An alternative framework, adopting a risk based approach, enables appropriate consideration of the goals and constraints to obtain a solution for structural fire resistance. This approach is sufficiently flexible that its component pieces can be improved and updated as new engineering techniques become available.