Camber in Roads
When the center of the carriage way is slightly raised above its edges on straight portion of the road is called as camber or cross slope.
The curvature provided to the surface of the carriage way is called as camber or cross slope.
Purpose of Providing Camber in Road
The main purpose of providing camber in carriage way is given below :
- To improve the architectural aspect of the road way.
- Camber is provided so that vehicles should be regulated to the proper lanes.
- It drain offs the rain water immediately from the road surface, so as to prevent it from entering into the sub-grade soil.
Also Read : Super Elevation and How to Calculate it
Also Read : What is Sight Distance (Highway Engineering)
Types of Camber
- Composite Camber
- Barrel Camber
- Sloped or Straight Camber
- Two Straight Line Camber
Composite Camber in Road:
The camber in road which consist of two straight slopes from edges with a circular or parabolic crow in the center of carriage way is called as composite camber.
This type of camber is easy in construction and maintenance.
Barrel Camber :
When the camber is having continuous curve either elliptical or parabolic then it is called as Barrel Camber.
Sloped or Straight Camber :
When two straight slopes from the edges joins at the center of carriage way then such camber is known as sloped or straight camber. This type of camber can easily be constructed and maintained.
This type of camber in road is provided in case of cement concrete road where very flat cross slope is required.
Two Straight Line Camber :
When camber consist of two straight lines steeper near the edges and flatter near the crown of carriage way it is known as two straight line camber.
IRC Recommended Road Camber for Different Road Surface
| Road Surface Types | Camber |
|---|---|
| High Type Bitumen Surface / Cement Concrete Surface | 1 in 60 - 1 in 50 (1.7 to 2 %) |
| Thin Bitumen Surface | 1 in 50 to 1 in 40 (2 to 2.5 %) |
| WBM Gravel Road Surface | 1 in 40 to 1 in 33 (2.5 to 3 %) |
| Earth Road, Footpath etc. | 1 in 33 - 1 in 25 (3 to 4 %) |
If the difference of an edge of the pavement (18 m ) wide and its crown is 30 cm ,then the camber in the pavement is
a) 1in 10. b) 1 in 20
c) 1 in 30. d) 1 in 60
Please anyone solve this for me.
Hello Bilal,
Glad that you asked your doubt. Let us help you out.
As given in the question, the horizontal distance is 18m and the crown height is 30cm (0.3 meter).
The easiest way to find out the camber is to just divide the horizontal distance from center of the road to its edge by the crown height.
Here,
horizontal distance from center to edge = 18/2 = 9 m
crown height = 0.3 m
camber = 9/0.3 = 30
hence the camber is 1 in 30
1/30. Which is 1 in 30