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Types Of Pavements & Its Design
Contents Types of Pavement Factors Affecting Selection of Pavement Pavement Components Factors to be Considered in Pavement
Design Flexible Pavement Design Methods Rigid Pavement Design Methods
Flexible Pavement
Called "flexible" since the pavement possess low bending strength and can transfer the wheel loads on the soil subgrade below by deformation action .
Eg: Bituminous and WBM roads
Rigid Pavement
Called “rigid” since the pavement possess good bending strength and can transfer the wheel loads on the soil subgrade below without deformation .
Eg: Cement concrete and RCC roads
Types Of Pavements
Flexible PavementsStructure
Surface courseBase courseSub-base courseSubgrade
StructureSurface courseBase courseSub-base courseSubgrade
Rigid Pavements
1. Type and intensity of traffic2. Availability of funds3. Subgrade soil and drainage conditions4. Availability of construction materials5. Availability of equipments, skilled and
unskilled labour6. Atmospheric conditions7. Time available for project completion8. Level of the area above mean sea level
Factors Affecting Selection Of Pavements
1. Subgrade2. Sub-base3. Base course4. Wearing course or Surface course
Pavement Components
1. Design wheel load
2. Subgrade soil
Factors To Be Considered In Pavement Design
3. Design life
4. Climatic factors
5. Pavement component material
6. Environmental factors
7. Drainage
8. Road geometry
1. Group Index method (G.I. method)2. CBR method3. California R value method4. Triaxial test method5. Burmister method6. Mcleod method
Flexible Pavement Design Methods
This method evolved from the soil classification methodsand was entirely empirical in its approach. • The Group Index (GI) is defined as: GI = 0.2a + 0.005ac+0.01bd
a = F - 35 (maximum 40) b = F - 15 (maximum 40) c = wL - 40 (maximum 20) d = Ip - 40 (maximum 10) F = Percentage by mass passing through 0.75mm, expressed
as a whole number
wL = Liquid limit(%) expressed as a whole number
Ip = Plasticity(%) expressed as a whole number
Group Index Method
CBR Method