The main point of difference in the structural behavior of rigid pavement compared to the flexible pavement is the critical condition of stress from the rigid pavement ist that the maximum flexural stress was occurring from the slab because of wheel load and the temperature changes where-as from the flexible pavement It's the distribution of compressive stresses.
Since the rigid pavement slab has tensile strength, tensile stresses are developed due to the bending of the slab under a wheel load and temperature variations.
So the types of pressures developed and their distribution inside the concrete slab that is concrete are quite different.
The rigid pavement doesn't get deformed into the shape of the surface as it could bridge the minor variations of the lower layer.
The cement concrete pavement slab may very well serve as a wearing surface in addition to an effective base course.
Therefore generally, the rigid pavement structure is made up of cement slab that is concrete, below that the granular base or sub-base-course can be provided (see above fig. 2).
Although the cement concrete slab may also be laid directly over the soil subgrade, this isn't preferred, particularly when the subgrade, consists of fine-grained soil.
Supplying a good base or sub-base course layer below the concrete slab that is concrete increases the pavement life considerably and thus works out more economical in the long run.
The rigid pavements are often designed, along with the stresses are analyzed using the elastic theory and assuming the pavement within an elastic plate resting over a elastic or a viscous foundation.
Difference Between Rigid Pavement and Flexible Pavement
The rigid pavement vs flexible pavement design approach varies. Design of rigid pavement is based on scientific design stresses of concrete, whereas the flexible pavement vs rigid pavement design is mostly empirical in nature.
Life of rigid pavement is more than the flexible one.
Maintenance of well deigned rigid pavement is practically very small, whereas the bituminous surface of flexible pavement needs frequent maintenance.
The initial cost of rigid pavement is much more than the flexible one. Considering the stage of construction, flexible pavement is preferred to the rigid pavement. The selection of a types of pavement depends on the availability of materials of construction.
Surface characteristics play another role in the selection of a types of pavement. A good cement surface is smooth, free from potholes and corrugations. Flexible pavement does not possess the above facilities.
An impervious layer of the pavement is essential for the sub-grade. Preference will always be the rigid pavement as concrete is impervious.
Traffic dislocation during construction for about a month takes place as concrete requires a minimum of 28 days for curing and setting. Inflexible pavement traffic is allowed to move on the pavement once it is rolled.