Based on the Structural behaviour, the road is generally classified into two categories: Flexible Pavement and Rigid Pavement.
Flexible Pavement
The Flexible Pavement consist of top wearing surface (mixture of bitumen or aliphatic compound and coarse aggregate) followed by sub base course -cum- drainage course. The bottom most layer of pavement is compacted soil course( has lowest stability among different course). Water bound Macadam roads is example of Flexible Pavement.Rigid Pavement
The Rigid Pavement is those type of pavement which posses higher flexural strength and modulus of elasticity value. These pavement are generally made from Portland Cement Concrete(CC) or Reinforced Cement Concrete(RCC). Rigid pavement are generally composed of plain cement concrete slab having specified strength laid over base course.For better understanding of these pavement type along their characteristic properties, Read the following difference between flexible and rigid road pavement:
S.No.
|
Flexible
Pavement
|
Rigid
Pavement
|
1
|
Load is distributed into Truncated Cone.
|
In case of rigid, uniform distributed load distributed due to slab
action.
|
2
|
Need Subgrade compaction i.e. need good quality of material
|
Lesser need of compaction i.e. even use less good quality of material
|
3
|
Flexible pavement has self-healing properties due to heavier loads.
|
Rigid Pavement has no self-healing properties.
|
4
|
There is grain to grain distribution of load.
|
No grain to grain distribution. Load are transferred by flexural
strength.
|
5
|
Temperature Change does not produce stresses in the pavement.
|
Heavy stresses are produced due to temperature change.
|
6
|
Flexible Pavement has lesser life span.
|
Rigid Pavement has large life span
|
7
|
Flexible Pavement have low initial cost and high maintenance cost.
|
Rigid Pavement have high initial cost and less maintenance cost.
|
8
|
Stage Construction is feasible.
|
No Stage construction is possible.
|
9
|
Flexible pavement is less economical in long run.
|
Rigid pavement is economical in long run.
|
10
|
Flexible pavement is lesser durable.
|
Rigid pavement is highly durable.
|
11
|
We can open the road for traffic after few hours.
|
Rigid Road takes more time for opening as time required for curing is
large.
|
12
|
Flexible pavement provide poor night visibility due to black colored top.
|
Concrete or Rigid pavement provide higher night visibility.
|
13
|
No joints are required.
|
Joints are required in rigid road to allow the change in shape due to
temperature change.
|
14
|
In case of flexible pavement, thickness of pavement is high as
addition of sub base course for drainage.
|
Thickness of pavement is less.
|
15
|
The stability depends upon compaction, particle interlocking and
cohesion properties.
|
The stability of pavement is provided by cement concrete slab by beam
action.
|
Other type of Pavements
Interlocking Cement Concrete Block Pavement
In Interlocking cement Concrete Block Pavement(ICBP), the pavement consist of cement concrete blocks of specified size, shape and strength is laid over well compacted soil sub grade or sub base course. The gaps between the block are filled with sand and vibrated so as to provide adequate compaction.
Read Also:
- Group Index Method- Design of Flexible Road
- California Bearing Ratio Test- Soil Test
- Shear Force and Bending Moment diagram
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