Abstract:36 specimens were tested under three different heating conditions corresponding to three different kinds of large space fires.Effective thermal conductivities of intumescent coatings were calculated based on the test measurements.TGA tests were conducted to investigate the effect of heating rate on fire performance of intumescent coating.The study found that the maximum temperature and heating rate were different under different heating conditions of large space fire

which resulted in different expansion rate and inner structure of intumescent char.The consequence of this is the different insulating properties of intumescent coating under different heating conditions.Increasing the heating rate and the temperature resulted in better insulating properties of intumescent coating.The maximum difference of 48.8% for λminwas obtained when the coatings were exposed to different heating conditions.In addition

the variation degree of effective thermal conductivities of intumescent coating under different heating conditions was affected by coating thickness，thin coating is more sensitive to the change of heating conditions.