Fracture behavior of a four-point fixed glass curtain wall under fire conditions

The cracking and subsequent fallout of glazing could significantly affect compartment fire dynamics by creating a new opening for air to enter. Twenty-four 1200×1200×6 mm³ soda-lime glass panes in eight different fixing forms were heated by a 500×500 mm² N-heptane pool fire to investigate the influence of fixing conditions on glass breakage and fallout. The time of crack initiation, behavior of crack propagation, heat release rates, central gas temperatures, glass surface temperatures and loss of integrity of the glazing assembly were investigated. The relationship between fixing form and crack behavior is discussed, based on the experimental results. The results show that all the cracks initiated at the supporting point and intersected rapidly, causing glass fallout. Mechanical stress caused by supporting pins and thermal stress caused by glass temperature difference (ranging from 48 °C to 159 °C) are the causes of breaking for this kind of curtain wall. It is concluded that various fixing locations have a significant effect on glass breaking. Among the eight cases, the glass panes whose supporting points were located at 10 cm (Case 1) or 5 cm (Case 8) from the edges performed best: these support locations are recommended in practical engineering because of the good fire resistance and structural beauty of such panes. © 2014 Elsevier Ltd.