The basic structure of constitutive models for remoulded or reconstituted soil behaviour is recalled first, making reference to elasto viscoplastic models and to incrementally non-linear laws. More recent developments on the modelling of natural soils and bonded geomaterials is presented next as an extension of the previous theories. Numerical simulations of tests on cemented soils are compared to experimental results. Finally a possible way of taking weathering into account is suggested. Weathering effects are investigated by comparing experimental test results and theoretical predictions for oedometric conditions. It is shown that, for certain values of the constitutive parameters, compaction bands can occur within the specimens.