Fracture behavior of framing coated glass curtain walls under fire conditions

Abstract Breaking glass and its subsequent fallout may markedly affect enclosure fire dynamics. However, little is known about the thermal fracture behavior of framing glass facades in different installation forms. Sixteen 600×600×6 mm 3 solar control coated glass panes, installed in exposed, semi-exposed and hidden frames, were heated by a 500×500 mm 2 n-heptane pool fire to investigate the influence of frame constraints on glass breakage and fallout. Measurements were taken of the time to breakage occurrence, heat release rates, incident heat flux, central gas temperatures and glass surface temperatures. Measurements in relation to crack initiation and propagation as well as loss of integrity of the glazing assembly were also recorded. The experimental results show that all cracks initiated at the edge of covered sections and intersected rapidly, forming islands. The maximum temperature difference and heat flux that the glass can withstand are primarily in the range of 50–90 °C and 9–15 kW/m 2 . Using the finite element method (FEM), the breakage mechanism is demonstrated, the predictions of which are in reasonably good agreement with the experimental results. Among four different installation forms, semi-exposed framing facades showed better fire resistance than exposed framing facades. Meanwhile, the fire resistance of hidden framing facades may depend on the fire location. It is intended that these results will provide practical guidelines for fire safety design.

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