Concrete spalling is caused when reinforcing steel within a concrete element begins to rust. The steel can expand up to seven times its original size, and in due time, exceeds the tensile strength of the concrete, and this results in concrete displacement and delamination.
1. Concrete Spalling
Concrete spalling, also commonly known as concrete cancer, is strata building
sydney that has flaked, broken or delaminated from the surface of the affected
area. It is a common problem with concrete structures and is easy to identify once
it has started.
Concrete spalling is caused when reinforcing steel within a concrete element
begins to rust. The steel can expand up to seven times its original size, and in due
time, exceeds the tensile strength of the concrete, and this results in concrete
displacement and delamination. Once manifested, if the problem is left
untreated, the rust spreads along the reinforcement which can lead to
devastating structural damage of both the steel and the concrete.
Although concrete spalling is a common problem, particularly in structures that
are located in a coastal or marine environment, the exact cause of concrete
spalling would relate back to the specific circumstances and should be assessed
case by case. However, quite often, several factors are at play.
Some of the most common causes, are the installation of reinforcing steel with
inadequate concrete cover – simply put, too close to the surface – which allows
surface water to react with it, cracking and damage to the concrete structure
allowing water to penetrate and come into contact with the steel reinforcement
and being the catalyst for the oxidation process which causes the formation of
rust.
Another cause is the use of incompatible metals in close proximity to each other
enabling a chemical reaction which can cause damage to the concrete and again,
allows water to penetrate the concrete structure.
It is of critical importance to address this situation when it starts to appear, and in
a timely manner. This is due to the fact that when the signs of deterioration of the
concrete are ignored residential builder, it is inevitable that more damage will
arise, lead to further and significantly higher repair costs and eventually affect the
integrity of the structure.
2. Furthermore, if the problem is not attended to, the concrete might separate into
pieces and these falling pieces could quite possibly cause damage to property and
serious injuries to people. This would put the property owners at risk of legal
proceedings due to negligence.
Once concrete begins to flake and delaminate, the repair cost would be larger
than the cost at the commencement of the problem. Moreover, attempting to
repair the problem, such as applying cement render to the affected area, is
incorrect and insignificant as it will not repair the damage, and despite the effort
and intention, the problem will continue below the surface. Treatment and repair
of the steel and concrete upon identification of the problem is the best and most
effective solution.
If you require professional advice with regard to identifying and repairing
concrete spalling, you should always err on the side of caution, and speak to an
appropriately qualified consulting engineer. You can contact Scope Building on
(02) 8073 4555 or by email info@scopebuilding.net.au, and we can assist you.
