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Blacktop Patching
The most common causes of asphalt deterioration are water accumulation in
areas of lower elevation, excessive loads on
the
asphalt, and the destructive
effects of vehicle oil and gasoline. Over time, water accumulation can
cause asphalt to
crack
and split severely, or
"alligator" as it is commonly referred to in the paving industry.
Bearing excessive weight can
cause
the asphalt to
sink, and oil and gasoline that seep into the asphalt cause further
deterioration.
Asphalt Patching Methods:
When area's of pavement deteriorate and need to be repaired S.O.S. corrects
the problem with one of two
methods.
1. Overlay Patching - is recommended when the underlying base is structurally
sound and is typically used on depressed
surfaces. This process is accomplished by cleaning the existing pavement ,
applying a tack coat (asphalt based glue), and
applying hot mixed asphalt. The new asphalt is then mechanically compacted.
Because the overlay patch is placed on top
of the existing pavement, the finished surface may be slightly higher than the
existing surface. The edges are blended in,
or feathered as much as possible.
2. Full Depth Patching - is used for more severe deterioration, especially
when the underlying base has been affected.
The damaged area's are squared off and mechanically cut using an asphalt
cutter and excavated to a depth of 2 inches
to 2 feet depending on the sub-surface conditions. New aggregate is then
added, if required, and compacted in preparation
for the new asphalt. Finally the new hot mix asphalt is leveled and compacted.
The perimeter edges of the patch are then
sealed with hot rubberized crack filler.