Cl – Cl – Cl – Cl – Cl – Cl – Cl –
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Poor concrete quality or shallow depth of cover
Chloride corrosion; good or poor concrete quality
Inadequate depth of cover
The majority of the reinforcement is located in the already carbonated zone of the concrete. In this case, carbonation protection would be too late and is thus pointless. The primary goal of surface protection is to protect the reinforce- ment from corrosion. If the concrete has already undergone carbonation, corro- sion can only be prevented by water- proofing.
Carbonation is slight, but corrosion nevertheless occurs due to the influence of chloride. A protective treatment which prevents penetration of chloride salts is required. Chloride corrosion may occur in as yet uncarbonated concrete even where concrete quality is good.
The reinforcement is close to or right at the surface of the concrete over the entire area (rusting). Additional cover with spray mortar/shotcrete is required. The material is so thoroughly compacted by the spraying process that it cannot undergo carbonation. Carbonation protection is thus not required.
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