3. Chemical and Organic Environment
Chemical precipitates cement particles together. Organic
matter influences surface forces and water adsorption properties,
which, in turn, increase the plasticity and compressibility.
Expansion of pyrite minerals in some shales and other earth
materials as a result of oxidation caused by exposure to air and
water has been the source of significant structural damage
(Bryant et al., 2003). Temperature changes may cause changes in
hydration states of some salts leading to volume changes.