Determination of critical fallout condition of tempered glass in an enclosure fire

Tempered glass is extensively used in modern high-rise buildings. However, in some instances the glass will break and fall out when subjected to a fire which will create a new ventilation condition, drastically changing the enclosure fire dynamics. In this work, eleven tempered glass panels with dimensions of 815 × 815 × 6 mm3 were heated by a pool fire placed in the center of a 1000 × 1000 × 1000 mm3 compartment. Parameters such as glass surface temperature, heat flux, failure time and fallout behavior, were all recorded. Weibull distributions were then employed to investigate the probabilistic characteristics of tempered glass fallout. Failure probability functions, survival probability functions, and failure probability density functions of tempered glazing were obtained and compared with those of clear and coated glazing. The critical temperature difference and critical heat flux, with 5% failure possibility for 6 mm-thick tempered glazing, are 301 °C and 36.17 kW/m2, respectively, which could be used as a conservative estimate for the safe design of glass façades in a fire.