Galvanization effect on steel frames exposed to fire

One of the materials mostly penalized in case of fire is the steel, because of its elevated thermal conductivity and the small dimensions of the structural member sections. Therefore, if the bare steel structures do not reach the required level of fire resistance it is necessary to use fire protections. Recent studies have shown that hot-dip galvanization which is already efficient to protect steel members from corrosion, can also provide a beneficial effect on the temperature of steel members exposed to fire thanks to a reduction in surface emissivity. This paper shows the main results of high-temperature small-scale tests on galvanized and not-galvanized steel plates, investigating and quantifying the effect of galvanization on the temperatures of steel elements, in a common and economical electrical furnace. Moreover, in the second part of this work, the effect of galvanization was assessed by varying the fire curve and the element section factors Am/V, underlining when it could be significant for improving structural fire resistance. An application of the galvanization benefit was also presented referring to advanced thermo-mechanical analyses of a single-story steel building, finding that, thanks to the galvanisation, this structure satisfies the required performance level, according to the fire safety engineering approach.