Impact resistance of archaeological ceramics: The influence of firing and temper

This work considers technological choices in the manufacture of utilitarian archaeological ceramics, in view of their role in the ceramics' physical properties and affordances. In this paper we present results of an experimental study which examined the influence of processing parameters on mechanical properties of clay-based ceramics. The influence of firing temperature, amount and grain size of aplastic inclusions on a ceramic's response to dynamic loads were determined experimentally, taking into consideration how this compares to the materials' response to static loads. Results show that the fracture strength under quasi-static loading increases with increasing vitrification and decreases with increasing amounts and size of aplastic inclusions. In contrast, while the presence of aplastic inclusions does reduce impact resistance, the amount and grain size of aplastic inclusions do not seem to play a significant role, both in terms of a ceramic's impact strength and fracture energy. This highlights the importance of considering the likely sources of mechanical stresses when assessing the affordances of a ceramic vessel.