Concrete Chemical Resistance |
Concrete can
be attacked by contaminants in water, soil or gases (e.g. air). Hazards also
occur in service (i.e. in tanks, industrial floors etc.).
·
Surface and ground water, harmful soil
contaminants, air pollutants and vegetable and animal substances can attack the
concrete chemically.
·
Chemical attack can be divided into two
types:
-
Solvent attack: caused by the action of soft
water, acids, salts, bases ,oils and greases etc
-
Swelling attack: caused mainly by the action
of water soluble sulphates
Measures
·
Concrete structure as impermeable as
possible, i.e. low porosity
·
Low water/cement ratio aim for < 0.45
·
Increase the concrete cover by 10 mm minimum
Concrete only has adequate resistance against
very weak acids.
Medium
strength acids degrade the concrete.
Therefore
extra protection of the concrete with a coating must always be specified for
moderate to highly aggressive acid attack.
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