How Does Activated Titanium Anodes Install in a Cathodic Protection System?
How Does Activated Titanium Anodes Install in a Cathodic Protection System?
On surface installation of a cathodic protection system, the activated titanium shall take the form of a mesh or grid, distributed in accordance with the cathodic protection system design, on the concrete surface. Titanium connectors shall be spot welded to the mesh or grid to distribute current to all component parts of the anode and to facilitate electrical connections to the anode. Where anode/cable connections are to be incorporated into the cementitious overlay, they shall be of a type and installed in a manner that can be demonstrated by trials or past projects to enable the design anode and anode/cable connection performance to be achieved. Non-metallic fixings shall be utilized to facilitate the fixing of the anode material to the surface of the concrete or to reinforcement/steel prior to pouring the concrete, and shall ensure that there are no short-circuits between anode and reinforcement/steel.
Installation into Recesses in Cover Concrete
The anode shall take the form of solid or mesh titanium strips or grids complete with the electrocatalytic coating, suitable for recessing into grooves cut into the cover concrete, or be activated titanium strips and grids with non-metallic fixings to facilitate installation onto exposed reinforcement prior to concrete placement. The size and distribution of the strips or grids shall conform to the cathodic protection system design and the maximum anode current density.
Embedded within the Structure
Activated titanium shall be embedded within the structure in one of the following ways:
a) electrocatalytically coated titanium in the form of a strip, mesh, grid, or tubes shall be embedded into a cementitious repair mortar in holes drilled into the concrete;
b) anodes of a similar form or platinum-coated titanium rods shall be used in conjunction with a conductive graphite-based backfill;
c) anodes of a similar form shall be cast into new construction for cathodic prevention or into concrete repairs for cathodic protection.
Where a backfill (e.g. graphite) is part of the anode system, its operating current density is based upon the dimensions of the hole drilled in the concrete, and the anode current density within the backfill shall conform to the cathodic protection system design (see 4.3) and shall be limited to values which can be demonstrated by trials or past projects to enable the requisite anode, backfill and anode/cable connection performance to be achieved. Where graphite backfill is utilized, the graphite shall be considered as the anode in calculating the minimum anode/reinforcement or other steel spacing.