Civil Engineering Reference
In-Depth Information
attached to the pile and filled with grout after connecting the zinc to the
reinforcement. All these systems and their performance in Florida are
discussed in Kessler et al. (2002).
In the UK, the first major development was of a proprietary anode for
patch repair. This has the appearance of a 'hockey puck' consisting of a disk
of zinc in a specially formulated mortar that prevents the zinc passivating.
Two pairs of wires protrude from opposite sides of the puck to be attached to
the reinforcing steel exposed during the repair. By installing galvanic anodes
within the repair (
Figure 4.9)
the 'incipient anode' effect is eliminated (see
Figures 4.3
an
d 4.4)
.
The 'hockey puck' has recently been developed further into a small
'yogurt pot' sized anode with a single connecting wire that can be inserted
into core holes in the concrete and wired together to produce a galvanic
discrete anode system (
Figure 4.10).
They have been used predominantly on
multi-storey car parks and on bridge substructures.
Since the maximum voltage that can be generated with zinc anodes is
extremely unlikely to generate hydrogen embrittlement, galvanic systems
have been used to protect prestressed concrete members. They are also
used on fusion bonded epoxy coated steel reinforced piles as the effects of
anode induced corrosion around the repair (courtesy of Fosroc Ltd).
