Concrete removal and surface preparation

Before patching carbonated concrete, the cracked and spalled concrete must be removed from around the rebar or as far as the carbonation front goes which ever is the lesser. The cementitious patch material is chosen to ensure that the steel is back in a high pH, alkaline environment. This will encourage the reformation of the passive layer to stop further corrosion. 

The choice of patch repair material is discussed later. Wetting or bonding agents are used to promote adhesion between the repair and the original 

Feathered edges and poor preparation aiiow breakway at edges and poor keying 

Concrete removal beyond the corroded area is not required for electrochemical treatment 

A summary of the properties and categories of hand held pneumatic breakers is given in Vorster et al. (1992). For concrete repair work breakers usually range from about 10 to 45 kg, or a maximum of about 20 kg 

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