Asphalt pavements are widely used for any application. However, every now and then,
these pavements get cracks. Why are there cracks and how do we determine the
causes of these?
In this post, these questions will be discussed.
Asphalt form cracks for a number of reasons.
Inadequate thickness of the pavement
Inadequate thickness of the base
No proper maintenance that causes deterioration
Paver seams get weakened
What are the defects on pavements to watch out for?
Alligator cracking
These cracks result from load related structural failure. They normally appear on
the wheel path because linear cracking from severe distress ends up as alligator
cracks. A full depth patching is needed to be performed in order to fix this.
Pot Holes
These are small, bowl-shaped depressions on the surface of a pavement that
can run deep into the asphalt layer. These holes are caused by infiltration of
moist.
Usually, when alligator cracks are not corrected, these become more severe that
cracks get interconnected creating pavement chunks that can cause holes when
driven over by vehicles.
Block cracking
Block cracks are cracks that form large rectangle like shapes. Unlike alligator
cracking, block cracking is caused by the inability of asphalt binder to expand.
The shrinkage of asphalt pavement causes these cracks.
Crack sealing will do the fix for less severe cracks. For cracks more than half an
inch, removing the cracked pavement and replacing with an overlay will be the
best solution.
Linear Cracking
This is also called longitudinal cracking. Linear cracks are parallel to the
centerline of the pavement. Pavement fatigue, poor joint construction are the
roots of this type of cracking. Fixing this would be similar to repairing block
cracks.
Cracking in the Edges
Poor drainage systems cause edge cracks primarily. Another reason for cracking
in the edges is poor pavement edge support. Heavy vegetation along the edges
can be a reason too. What happens is that the base materials get weakened
when they settle.
To correct this, the initial step is to remove the vegetation near the edge of the
pavement. Drainage issues should be fixed after so reconstruction will be
possible.