Based on the Szirtes’ modern dimensional analysis (MDA), the authors apply the theory to a real structure in order to validate by experimental measurements its applicability. After a presentation of the basic elements of the model law (ML), deduced for two relevant cases, the authors conceived the set of prototypes and models, based on the case of an actual construction pillar, physically performed at scales of 1:1, 1:2, and 1:4. The combination of these structural elements, made at different scales, resulted in three sets of prototypes and models. In this paper, taking into consideration the ML for two relevant cases, the following are presented: the original test stand of these structural elements; block diagram of the original electronic heating and control system; the basic considerations regarding the particularity of this heating system from the point of view of heat transfer; measurement data, obtained for both nonthermally protected elements and for those protected with layers of intumescent paints. In the last part of the paper, the values obtained by rigorous direct measurements with those offered by the ML on the elements considered as prototypes and models are compared. Almost identical values were obtained from the direct measurements with those provided by the ML, thus resulting in the validation of these laws. The same thermal regimes were applied to all these structural elements, with registration of every parameter related to these thermal regimes. Depending on the role of a structural element within a certain set (prototype-model), some of the measurement data were considered as data acquired directly through measurements, and others served as reference elements for those for which we had to obtain through the model law. In the last part of the paper, the sizes obtained by rigorous direct measurements are compared with those offered by the model law on the elements considered as prototypes and models. Identical practical values of the quantities were obtained from the direct measurements with those provided by the model law, thus resulting in the validation of these laws.

Summary The authors present the first stage of their theoretical and experimental investigations focused on the fire protection of the steel structures using intumescent paint. In this initial stage, their results concerning the temperature distribution law (the theoretical law is validated by effective meticulously conducted measurements) are described. Their original testing bench destined to perform high‐accuracy monitoring of the temperature distribution along straight bars, having a given αg angular positioning with respect to the vertical direction is also described. By involving this testing bench in meticulously conducted experiments, the authors obtained both the effective temperature distribution along the bars and also validated the theoretical (exponential) thermal distribution law. By searching experiments, they also validate the m = const. hypothesis with respect to the massive cross‐sectional bars. Among their further goals, one can mention the searching experimental analysis on the validity of the m = const. hypothesis for the tubular cross‐sectional bars, followed by a combined experimental and numerical analysis of the 2‐D and 3‐D (unprotected and protected with intumescent paint layer) structures, as well as the paint layer's thickness optimisation, too.

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