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By : Mr. Nirmal Maisuria (B.tech Civil) (Highway Design Engineer)
Type of Pavement : •B- Bituminous•R- Rigid•E- Earthen
In Flexible pavement :
•Alligator Cracking /Longitudinal/Transverse Cracking/Block Cracking
•Edge Cracking
•Patching
•Rutting
•Potholes
•Drainage
•Roughness
• Good• Poor• Fair
GOOD
FAIR
POOR
• The roughness of a road is determined by the severity of uneven surfaces, corrugations, sags, humps, frost heaves and the previous survey conditions.
• Longitudinal / Transverse Cracking : N - Narrow ; W - Wide
• Alligator / Block Cracking : L - Low ; M - Medium; H - High
•Alligator cracks are interconnected cracks, forming a series of small blocks resembling an alligator’s skin. This occurs when the sub-base gravel fails to provide adequate support for the asphalt pavement. It is also known as fatigue cracking, and repeated heavy loads and moisture create excess flexing of the surface.
• LowLongitudinal disconnected hairline cracks no greater than
1/8 inch wide running parallel to each other; initially may be only a single crack in the wheel path but could also look like an alligator pattern.
• ModerateLongitudinal cracks in wheel path(s) forming an alligator
pattern; cracks may be lightly spalled and are about an 1/8 to 1/4 inch wide.
• HighCracking has progressed so that pieces appear
loose with severely spalled edges; cracks are probably ¼ inch wide or greater; pumping of fines through the cracks may be visible on the pavement surface; potholes may be present.
• The failure can be either in the surface, base or sub base.
• Cracking usually first begins in the wheel path, usually as longitudinal cracking Further stress creates an alligator pattern.
SEVERITY:•LOW•MEDIUM•HIGH
• Longitudinal cracks are individual and run parallel to the centerline. Transverse cracks run perpendicular to the centerline. They are caused by inadequate bonding between paving lanes or asphalt shrinkage from low temperatures.
1) Low2) Medium3) High
located within 1-2 feet of the edge of the pavement.
Low: Hairline cracks just beginning to show; cracks are random with no pattern; cracks may be up to ¼ inch wide
Medium:Cracks are wider, being from 1/4 inch to 1/2 inch in width or an alligator pattern of cracks more than a foot in width measured from the pavement edge.
High:Cracks greater than 1/2 inch, or alligator sections which have failed; pieces of pavement may be loose, or missing, or potholes may be present
Pavement edge distress can result in worsening of wheel path condition, allow moisture intrusion in the subgrade soils and base materials.
This cracking may occur in combination with other distresses.
• Rutting is the displacement of pavement material that creates channels in the wheel path and is sometimes referred to as channeling.
No visible rutting (<1 in.)
Rutting visible (>1 in.)
LengthDepth
• Severity of Ravelling : L - Low ; M - Medium; H - High • Length• Width
• Potholes arise when the wearing surface disintegrates under traffic, due to inadequate structural strength in one or more layers of the pavement. They are bowl-shaped voids and are often located in areas of poor drainage
LengthDaiWidth
Area
• . Patches are portions of pavement that have been removed and replaced, usually to repair defects in the pavement. Problems occur when the patches crack, settle, or distort.
Length
Dai
Width
Area
• Good: The quality and condition of the patch is excellent. Patches show no distress such as cracking or raveling.
• Poor: Patches are showing some distress. Edges of the patch are abrading. Hairline cracks are beginning to show. Patches are failing showing multiple cracks and distortion or the edges of patches are separating.
Good :
Poor:
• Inadequate drainage is important to document because of the long-term affects of moisture on pavement. Rain falling on pavement should be efficiently directed to drains and catch basins. Poor drainage can damage the concrete, weaken the sub-grade, etc.
• LOW / MEDIUM/ HIGH• Length• Width• Area
Length in mt.
• Edge Drop in mm• Length
Mr. Nirmal MaisuriaMr. Nirmal Maisuria(B.tech Civil)(B.tech Civil)
Designation: Highway Design EngineerDesignation: Highway Design EngineerCompany: Translink Infrastructure Pvt. Ltd.Company: Translink Infrastructure Pvt. Ltd.Contact: 9586703077 Contact: 9586703077 Email id: [email protected] id: [email protected]
