Structural fire resistance: Rating system manifests crude, inconsistent design

(in lingua inglese)

This study presents and compares example buildings that highlight the above shortcomings in the current grade structure and show how a applying a ‘‘consistency of crudeness’’ in the design method, through the use of refined fire resistance ratings, leads to more robust and dependable outputs. Refined grades would also reduce the significance of movement between notional thresholds or ‘‘magic numbers’’ and, therefore, the focus of design and approvals discussions regarding performance-based methods could move away from comparing the outputs of the engineering analysis with the prescriptive guidelines, and towards the validity of the methodology, assumptions, input parameters and other facets of the design.