A METHODOLOGY FOR THE FIRE RESISTANCE TESTING OF STRUCTURAL COMPONENTS AT REDUCED SCALE

The full scale fire resistance test forms the basis of acceptance of s tructural integrity in fire. However, such tests are too expensive to provide more than a limited amount of test data of parametric signific ance as a means of fully exploring a width of structural responses, re quired for research purposes as underpinning to the formulation of des ign guidance. In this paper a methodology for the fire testing of redu ced-scale structural models, previously outlined in other fire enginee ring journals, is presented for dissemination to the wider testing com munity. The principles of scale modeling applied to general structural testing and the specific requirements for scaled thermal modeling are detailed. Their application to the formulation of a new model fire cu rve for reduced-scale modeling is defined. An initial normalized tempe rature distribution condition in a test specimen requires the impositi on of an inverse scale incident heat flux rule and a scale squared tim e scale rule. The increased flux requirement can be accommodated by an enhanced temperature axis formulated by consideration of convective a nd radiative surface heat transfer processes. An alternative suggestio n to control model test furnaces by heat flux instrumentation is also postulated. Finally, experiences with the application of the methodolo gy to some wide-ranging research studies on brickwork compartment wall s, reinforced concrete floor slabs, and steel columns in standard fire tests are presented to illustrate different facets of the application of the methodology. Further applications to ''natural'' fire tests pe rformed within the Cardington Frame program are also referenced.