Mateiral Models and Classification

There are different ways to classify different pavement materials. For CalME, materials are classified based on their mechanistic (stiffness and damage models) behaviors. Specifically, materials are classified by the sets of models needed to describe how they will perform in the M-E design process. The following figure shows the hierarchical classification of materials included in the Standard Materials Library in CalME.

(Note: each box contains the name of the material group followed by a list of models required for the material group, and a list of materials using the abbreviations of that appear in CalME. The arrows connecting different boxes indicate the “is a” relationship.)

The figure illustrates the hierarchy of materials in the Standard Materials Library arises out of the relations between different material classifications. For example, asphaltic material has an “is a” relationship with pavement material. In other words, asphalt material is a specialized type of pavement material. This implies that all models selected for pavement material (heat transfer and linear elasticity) are applicable to asphaltic material as well. In addition, asphaltic material has its own set of material models, including asphaltic stiffness master curve, asphaltic binder viscosity aging, etc. In CalME, asphaltic material has two stiffness models: the linear elasticity model inherited from the generic pavement material, and the asphaltic stiffness master curve model that is specific to the asphaltic material. The asphaltic stiffness master curve accounts for the effects of loading time and temperature, and provides the Young’s modulus needed for the linear elasticity model for use in the response models.

CalME includes three specialized groups of pavement materials: asphaltic material, non-asphaltic bound material, and unbound material. The non-asphaltic bound material can be further specialized into cementitiously stabilized material.

The ensuring subsections, which describe each type of material and the associated material models.