On crack density, crack porosity, and the possibility to interrelate them

Crack density parameter – in whose terms the effective elastic or conductive properties are expressed – contains no reference to crack openings and hence to “crack porosity”. This is consistent with the fact that these properties do not depend on the openings (provided they are small, aspect ratios smaller than 0.08–0.10). However, crack density may be difficult to measure experimentally. On the other hand, crack porosity is easier to estimate (for example, from the specific weight data). It is shown that, under certain conditions, crack density can be estimated from the porosity data.