Experimental study on fire performance of double-skin glass facades

Abstract

This article presents an experimental study to investigate the fire performance of double-skin facades made with double glazing. First, preliminary tests were carried out to study the breakage of double glazing using a window assembly exposed to fires located in a small burn room. The glazing was 6-mm-thick toughened glass. The results show that at the time when the glass panes broke, the temperatures on the exposed surface of the first layer reached about 600°C–800°C. Second, a full-scale facility was built to study double-skin glass facades exposed to room fires as well as fire spread in the cavity. The internal skin was double glazing using 6-mm-thick glass, and the external skin was double glazing using 12-mm-thick glass with an intervening gel layer. Three fire scenarios with different heat release rates were tested. The temperatures on the outer glass of the internal skin and the inner glass of the external skin on the upper floor were lower than 300°C, which was not high enough to break the upper glass. For the fire scenario with a maximum heat release rate of 2.0 MW, the inner glass of the external skin broke on the first floor opposite to the fire source. The intervening gel layer ignited, and it caused failure of the external skin. The smoke could be exhausted directly to the atmosphere through the broken area on the external skin, and this helped to release the heat trapped in the cavity.