In Japan, fire tests are not required to evaluate fire performance of curtain walls and instead of fire tests, it is required to use the materials specified in the technical advice of curtain walls. Required fire performance of spandrel area and vision area are different because of another performance of curtain walls. Therefore fire performance of vision area and spandrel area are considered separately but even if parts of curtain walls have fire resistant performance, the performance of whole curtain wall is not confirmed. The purpose of this study was to clarify behavior of the mullions of typical stick system aluminum curtain walls exposed to standard fire. There are no standard testing methods to evaluate fire resistance performance of curtain walls in Japan, so five types of heating test methods are considered in this study to heat areas of curtain walls with different fire resistance performance. The experiment parameters are heating surface, the size of test specimens and the shape of mullion sections. Heating types are shown below 1. Test specimen of vision area and spandrel area is heated from inside for 20 minutes. 2. Test specimen of vision area and spandrel area is heated from outside for 20 minutes. 3. Test specimen of spandrel area is heated from inside for 1 hour. 4. Test specimen of spandrel area is heated from outside for 1 hour 5. Test specimen of spandrel area is heated from inside and outside for 1 hour Findings are as follows. 1) Fire insulation material of mullions that protects mullions from heating from inside prevents radiation cooling from unexposed side of mullion in case of heating from outside. Therefore, temperature of mullions with insulation materials will be higher than mullions without insulation materials. When determining the thickness of insulation material of mullions, both heating from inside and heating from outside should be considered. 2) Deformation of mullions is determined by difference of thermal expansion between inside and outside and compression force with difference of Young's modulus in the section of mullions. Function of connection part called joint sleeve is effected by deformation of mullions. Deformations of mullions is determined by distance between supporting points of mullions, sectional shape of mullions, the temperature difference in section of mullion, temperature of mullions and restrain condition of mullion end. 3) When test specimen of only spandrel area heated from inside, there are no thermal transmission from mullions of vision area with no insulation materials and temperature of mullions are lower than whole curtain walls are heated from inside. When fire resistant performance of spandrel area is evaluated, thermal influence from vision area should be considered.
