Flexible and Rigid pavement

• Layers in flexible pavement?

  subgrade, sub-base, binder course, surface course
• Types of flexible pavements

  • Conventional layered flexible pavement
  • Full-depth asphalt pavement
  • Contained rock asphalt mat (CRAM)
• Conventional flexible pavements are layered system with high quality expensive materials are placed in the top where stresses are high, and low quality material placed in lower layers
• Full depth asphalt pavement are constructed by placing bituminous layers directly on the soil sub-grade.
• Full depth asphalt pavement suitable when there is high traffic and local materials are not available
• Contained rock asphalt mats are constructed by placing dense/open graded aggregate layers in between two asphalt layers. This is to reduce vertical compressive strain on soil sub-grade and protect from surface water
• Conventional pavement layers

  • Hot mix asphalt (HMA)
  • Porous asphalt
  • Warm mix asphalt
• Types of rigid pavement

  • Jointed plain concrete pavement (JPCP)
  • Jointed reinforcement concrete pavement (JRCP)
  • Continuously reinforced concrete pavement (CRCP)
• Continuously Reinforced Concrete Pavement (CRCP): Continuously reinforced concrete pavement uses continuous steel fibers instead of discrete bars or meshes. This provides better durability and resistance against cracks.
• Jointed Reinforcement Concrete Pavement (JRCP): In this type of pavement, steel bars or mesh are used to reinforce the concrete slab. These reinforcements prevent cracking due to thermal expansion and contraction.
• Jointed Plain Concrete Pavement (JPCP): Jointed plain concrete pavement consists of slabs that are laid parallel to the direction of travel. The joints are formed at regular intervals.
• Advantages of CRCP over JRCP include improved fatigue life, reduced maintenance costs, and increased safety due to smoother riding surfaces.
• Types of joints in rigid pavement

  • Expansion
  • Contraction
  • Hinge
  • construction