Essay On Pavement

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1.2 TYPES OF PAVEMENTS Highway pavements are of two types;
a. Flexible pavement

b. Rigid pavement

1.2.1 Flexible pavement These pavements which reflect the deformation of subgrade and the subsequent layers to the surface. Flexible, usually asphalt, is laid with no reinforcement or with a specialized fabric reinforcement that permits limited flow or repositioning of the roadbed underground changes.
 The design of flexible pavement is based on load distributing characteristic of the component layers. The black top pavement including water & gravel bound macadam fall in this category.
 Flexible pavement on the whole has low or negligible flexible strength flexible in their structural action. The flexible pavement layers transmit the vertical …show more content…

 To be sustained by this layer, in addition to wear and tear, the lower layer have to take up only lesser magnitude of stress as there is no direct wearing action due to traffic loads, therefore inferior material with lower cast can be used in the lower layers. A typical sketch of flexible pavements is given in Figure 1.2. Figure1.2 Flexible Pavement
1.2.2 Rigid pavement The rigid characteristic of the pavement are associated with rigidity or flexural strength or slab action so the load is distributed over a wide area of subgrade soil. Rigid pavement is laid in slabs with steel reinforcement. The rigid pavements are made of cement concrete either plan, reinforced or prestressed concrete. Critical condition of stress in the rigid pavement is the maximum flexural stress occurring in the slab due to wheel load and the temperature changes. Rigid pavement is designed and analyzed by using the elastic theory.A typical sketch of rigid pavement is given in Figure 1.3. Figure1.3 Rigid Pavement.
Advantages of Rigid Pavement
 Rigid pavement lasts much, much longer years compared to flexible

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