The objective of this work is to analyze the crack and fallout of toughened glass with thicknesses of 6 and 10?mm in enclosure fires. A series of full-scale experiments are conducted in the ISO 9705 fire test room using pool fires with different pan sizes, which are located at the center of the combustion room. The temperature differences between the exposed regions at the fire side and the shaded regions at the ambient side for typical edge positions are measured and compared. The results of both 6- and 10-mm-thick toughened glass suggest that the whole piece of toughened glass cracks and falls out completely when any region of the pane breaks. Relatively large window vents may come into being if the toughened glass breaks. The experimental results also preliminarily show that the critical breakage temperature difference for the 6-mm-thick toughened glass is about 330380°C, whereas the corresponding values for 10-mm-thick toughened glass are approximately 470590°C. It is suggested that the critical breakage temperature difference is larger for thicker toughened glass. The experimental phenomena for both 6- and 10-mm-thick toughened glass indicate that horizontally partitioning windows into several small panes with frames may be helpful and important to prevent the whole large and tall toughened glass from falling out completely in enclosure fires.
