CONSTRUCTING THE ROAD BED

• ROAD BED - The prepared location for a road, including its foundation or base layer. It is the foundational layer that supports the entire roadway structure. It consists of the natural soil or prepared material upon which the road is built.
• ROAD LAYER:

  SURFACE COURSE - The top layer of the pavement structure. It is designed to provide a smooth, durable, and skid-resistant surface.
• ROAD LAYER:

  The base course is the layer of material placed directly beneath the surface course and above the sub-base.
• ROAD LAYER:

  Sub-base course is a layer of material laid between

  the subgrade and the base course. Its role is to provide added support,

  distribute loads more evenly, and enhance drainage.
• ROAD LAYER:

  The subgrade course is the underlying layer of natural soil or compacted fill that serves as the foundation for a road or pavement system.
• Two type (2) of pavements:

  1. Flexible Pavement consist of multiple layers of material, including an asphalt surface course, a base course, and a sub-base, all placed over a prepared subgrade.
  2. Rigid Pavements are primarily constructed from concrete and consist of a single, solid layer that rests directly on the prepared subgrade or a base layer.
• STEPS IN PREPARING THE ROAD BED (DPWH Standard):

  CLEARING AND GRUBBING - Clearing is the removal of all vegetation on the surface, and grubbing is the removal of roots that may remain in the soil.
• STEPS IN PREPARING THE ROAD BED (DPWH Standard):

  EXCAVATION is an essential part of the construction process, as it involves removing soil and rock from a specific area to create a foundation for a new structure. This is often necessary to level the ground and prepare it for the construction of a building or other structure.
• STEPS IN PREPARING THE ROAD BED (DPWH Standard):

  EMBANKMENT - It consists of the construction of *blank* in accordance with the conformity of the lines, grade sand dimensions shown on the plans or established by the Engineer
• STEPS IN PREPARING THE ROAD BED (DPWH Standard):

  SUBGRADE PREPARATION - Repeated operation of fine grading and compacting the subgrade until the specified lines, grades, and cross- sections have been obtained and the materials are compacted to the specified depth and density.
• TYPES OF EXCAVATION:

  • Roadway excavation

  • Unclassified excavation

  • Common excavation

  • Rock excavation

  • Muck excavation
• Checking Subgrade Density:

  Subgrade compaction Grading, shaping, and compacting natural

  subgrade materials preparatory to laying an aggregate base or pavement
• Checking Subgrade Density:

  Subgrade Elevation, after final grading (often called fine-grading) the *blank* should generally conform closely to the construction plan subgrade elevation.