Until now, only experiments of short duration have been undertaken to determine the strength characteristics of glass, in particular of glass containers. The existing test methods are: The bursting pressure test or the rapid breakage pressure test; the one-minute test and the one-minute incremental pressure test; the thermal shock resistance test; & the optical polarisation test. As in practice, glass containers are often subjected for long periods to excess internal pressure, this raises the question of their behaviour under long duration, continuous loading. From other fields, it is known that short duration experiments do not permit conclusions about long-term behaviour to be made, ie with many materials, it is necessary to study the long-term behaviour, as some properties change with time because of the interaction of the structure and chemical composition of the materials with the influences of environment or operating conditions. The duration of the stress also greatly affects the strength. To follow up these questions, experiments of long duration were carried out.
