What is flexible pavement in road construction?
What is flexible pavement in road construction?
In simple terms, a flexible pavement can be defined as a pavement layer comprising of a mixture of aggregates and bitumen, heated and mixed properly and then laid and compacted on a bed of granular layer.
What is road cross section?
In the cross section of roads it is that portion of the roadway between the outer edge of the outer traffic lane and the inside edge of the ditch, gutter, curb or slope.
How much layers are include in flexible pavements?
Typical layers of a conventional flexible pavement includes seal coat, surface course, tack coat, binder course, prime coat, base course, sub-base course, compacted sub-grade, and natural sub- grade. Seal Coat: Seal coat is a thin surface treatment used to water-proof the surface and to provide skid resistance.
What is flexible pavement structure?
Flexible pavements are constructed using bituminous materials. Flexible pavement layers reflect the deformation of the lower layers on to the surface layer (e.g., if there is any undulation in sub-grade then it will be transferred to the surface layer).
What are the types of flexible pavement?
Types of Flexible Pavements
- Conventional layered flexible pavement,
- Full – depth asphalt pavement, and.
- Contained rock asphalt mat (CRAM).
What are the purpose of flexible pavement?
Objective of Flexible Pavements To limit the recoverable or elastic deformation of the pavement within the permissible limits so that the pavement can sustain a large number of repeated load applications during the design life, without resulting in structural damages due to fatigue failure of the pavement layers.
What are the three layers of a flexible pavement?
A typical flexible pavement structure (see Figure 2) consists of:
- Surface Course. The layer in contact with traffic loads.
- Base Course. The layer immediately beneath the surface course.
- Subbase Course. The layer between the base course and subgrade.
What is the function of flexible pavement?
The primary function of a pavement is to transmit loads to the sub-base and underlying soil. Modern flexible pavements contain sand and gravel or crushed stone compacted with a binder of bituminous material, such as asphalt, tar, or asphaltic oil. Such a pavement has enough plasticity to absorb shock.
What are the types of road pavement?
Different types of pavements
- Hot Mix Asphalt. Also referred to as HMA, blacktop or bitumen, and one of the most common asphalts poured in the United States, this is an economical and durable choice.
- Porous Asphalt.
- Fine or Coarse Grade Asphalt.
- Stone Mastic Asphalt.
- Concrete.
- Composite.
What is a typical cross section of flexible pavement?
A typical cross section of the flexible pavement is shown below. Based on this, flexible pavement may be constructed in a number of layers and the top layer has to be of best quality to sustain maximum compressive stress, in addition to wear and tear. The lower layers will experience lesser magnitude of stress and low quality material can be used.
What are the components of road cross section?
Road Structure Cross Section is composed of the following components: 1. Surface/Wearing Course in pavement cross section: The top layers of pavement which is in direct contact with the wheel of the vehicle. Usually constructed of material in which bitumen is used as binder materials.
What is the function of sub grade in flexible pavement?
The sub-grade is the lowermost layer of the flexible pavement and usually consists of a compacted layer of natural soil. Its primary function is to bear all the imposed stresses from the upper layers. A typical cross-section of flexible pavement is shown below in fig.2. 3. Types of Flexible Pavement
What is the difference between rigid pavement and flexible pavement?
In rigid pavements, the stress is not transferred to the lower layers by grain to grain transfer as in the case of flexible pavement layers. It has the capability to transmit the traffic load stresses through a much wider area below the pavement. Rigid pavement usually built as plain concrete with dowel bars.
