Due to loading on the strong axis of glass panes, different fracture mechanical behaviour has to be admitted than due to the loading on the weak neutral axis. Existing models to describe the structural safety of glass can not easily be adopted.

The load-bearing of reinforced glass panes varies with the degree of prestressing due to increasing residual stresses of heat strengthened achieved by using reinforced heat strengthened glass.

This article offers a model to calculate the stresses of I-Beams with and without the appearance of cracks (Mode I and II) and the load-bearing behaviour of the adhesive joint of reinforced glass, such as distances between cracks, number of cracks and load introducing length.

Safety-considerations taking into account the load carrying-behaviour of reinforced glasses with different residual stresses due to heat strengthening are shown.