Classification of Pavement

Pavement is the surface layer of a road that is designed to provide a smooth and durable driving surface. Pavements are classified based on their structural behavior, which is determined by the characteristics of the materials used in the pavement layers.

Flexible and Rigid Pavements

Pavements can be classified into two categories: flexible and rigid pavements.

Flexible Pavements

Flexible pavements are those pavements that deflect under traffic loads. They are designed to distribute the traffic load through the different layers of the pavement. Flexible pavements are made up of three layers, namely the wearing course, base course, and sub-base course. The wearing course is the top layer, and it is designed to withstand the traffic load and protect the underlying layers.

Rigid Pavements

Rigid pavements are those pavements that do not deflect under traffic loads. They are designed to transfer the traffic load directly to the subgrade through the rigid slab. Rigid pavements are made up of a single layer of Portland cement concrete.

Classification based on Subgrade

Pavements can also be classified based on their subgrade, which is the natural soil or rock on which the pavement is built. The subgrade provides the foundation for the pavement layers and must be able to support the traffic loads without significant deformation or settlement.

Flexible pavements are built on weaker subgrades, while rigid pavements are built on stronger subgrades.

Answer

The pavement is classified as flexible or rigid based on its subgrade. The subgrade is the natural soil or rock on which the pavement is built, and it provides the foundation for the pavement layers. Flexible pavements are built on weaker subgrades, while rigid pavements are built on stronger subgrades. The subgrade's ability to support the traffic loads without significant deformation or settlement determines the type of pavement that should be built.