Introduction
The designing of pavement is one of the challenging tasks in Transportation Engineering. Rigid pavement and Flexible pavement are the two types of road pavement design methods. The pavement surface should be durable and can withstand the load acting from the wheel tires.
The functional requirement of Highway pavements are
1- Flexible pavement and Rigid pavement have good riding quality.
2- It should be less slippery.
3- It should be firm.
4- It should have sufficient friction without affecting the power of the vehicle.
Flexible pavements are constructed of several thicknesses of asphalt or bituminous concrete layers overlying a base of granular material on a prepared subgrade. They spread the concentrated aircraft wheel loads throughout their depth until the load at the base of the pavement is less than.
1- Load transfer is from grain to grain to the lower layers
2- The design greatly depends upon the subgrade strength
3- IRC 37-2012 code is used for designing flexible pavement
4- The stability of flexible pavement depends upon aggregate interlock, particle friction, and cohesion
5- Flexible pavement shows the deflection of the subgrade at the surface of the pavement.
6- Design life is 15 years.
Rigid pavements are constructed of portland cement concrete slabs resting on a prepared subbase of granular material or directly on a granular subgrade. Load is transmitted through the slabs to the underlying subgrade by flexure of the slabs. Flexible pavements are constructed of several thicknesses.
Rigid Pavement
1- Rigid pavement has a good flexural strength which serves as the major factor of design.
2- Rigid pavement has a concrete layer at the top, the base course and soil subgrade are under it.
3- Rigid pavement can distribute the load over a wide area because of its high flexural strength.
4- Load transfer is done by slab action.
5- The total thickness of the pavement is lesser than flexible pavement.
6- IRC: 58-2011 is used for designing Rigid pavement.
7- Design life is 30 years.
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