Concrete Spalling , now what?
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Concrete spalling is a very serious event in
your home’s life, so treat it as such.
Spalling is the name for the result of moisture
penetrating the concrete and attacking the
steel re-enforcing. Concrete is a porous
material, which if left unprotected, will slowly
allow water to penetrate it. When this moisture
comes in contact with the steel re-enforcing
the steel starts to oxidize (rust). As it rusts the
steel expands. This expansion has nowhere to
go and so it cracks the concrete. Also,
concrete is subject to deterioration caused by
absorption of moisture and thermal expansion
and contraction. Extreme temperature ranges
can cause freeze-thaw cycles. Moisture
absorbed by the concrete expands and
contracts with the temperature changes and
the resulting mechanical action causes
fractures and spalling. Airborne pollutants,
such as carbon dioxide, can cause adverse
chemical reactions, which can cause surface
deterioration. This can continue until the
concrete is in need of replacement.
The early stages of spalling concrete will not
affect the safety of the building. However, the
spalling concrete should be repaired as soon
as possible before the steel bars corrode
further and damage larger areas hence the
term ‘concrete cancer’.
If the area affected is small and shallow, you
may be able to correct the problem yourself.
However, if it is larger and/or if it is a part of
the structural strength of your home get a
professional.
Injecting epoxy into them after a thorough
cleaning can arrest many small cracks
development. Be sure it is only a shallow
crack or all you are doing is hiding your
problem and it will continue to grow, just out of
sight.
The moral of the story is, protect your concrete
with a good quality coating.
