Super toughness
A liquid is super viscous when it has the properties of liquids (for example, is amorphous ), but the flow rate of such a liquid is so slow (i.e. the viscosity is so high) that one has the impression that the liquid does not flow at all.
Such liquids include, for example, pitch or asphalt ; see Pechtropfenexperiment . Also, glass is sometimes attributed to the property of the super toughness, as it physically is a solidified liquid. On the other hand, there are also metallic glasses that have been proven to be elastic solids . Furthermore, no flow behavior can be determined for various types of glass that are used in optical applications. Such behavior would noticeably influence the properties after a very short time, in the range of days or weeks.
The property of super toughness is used, especially in road construction . The asphalt is paved in a warm or hot state (60 ° C and more) and is therefore easily malleable and flowable (i.e. not super tough). After it has cooled down, however, it becomes almost solid and only flows so slowly that the tensions that arise in the asphalt can still be compensated for by temperature fluctuations. There are thus no expansion joints such. B. required for concrete roadways.