  The research reveals the existence of a constant characteristic time of
preparatory micro-structural processes before the onset of macro-failure at
various high loading rates of brittle and quasi-brittle materials. The presence
of this characteristic is analysed based on available data in the literature
from dynamic tests for uniaxial compression and splitting. It is shown that the
characteristic time can be determined experimentally and used to calculate the
strain rate dependencies of either critical failure stresses or time to
failure, at least in the case of linearly growing loads. In addition, it is
discussed that the presence of this constant parameter opens up a prospective
opportunity for research and development of new methods for assessing the
structural-temporal and scale characteristics of the strength and failure of
materials under dynamic loads.
