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The Recycling Process
The Problems With Old Asphalt Pavements
 Asphalt
pavements eventually wear out. Just like old cars or clothing, the
effects of wear and climate will destroy the pavement. The roads require
costly maintenance to stay in service.
Asphalt pavements typically fail in several ways. The most common
include:
Fatigue cracking - Traffic causes repeated strain in the
surface and eventually the asphalt cracks.
Rutting - Channelized traffic loads shift the materials
in the surface, base, and subgrade, leaving depressions or ruts
in the pavement.
Shoving - The forces created by cars and trucks braking
and stopping separate the surface material from the underlying base.
Loss of base or foundation support - Moisture degradation,
traffic overloads,
or subgrade failure can cause the pavement base to fail.
The type of failures mentioned above are especially prevalent in
secondary roads, where pavement structures are typically light,
and are often not designed for today’s increased traffic levels.
Repairs can be costly. A typical maintenance treatment, like a thin
asphalt overlay, will only temporarily cover up the problem. Other
options, such as thick overlays or removal and replacement, are
expensive.
Text and Photos courtesy of Portland Cement Association www.portcement.org
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