Advantages of durAnode®Introduction
The first durAnode® was manufactured and installed some twenty years ago. The purpose was to make hot spot cathodic protection of an especially aggressive exposed area. The original anode used a simple ø3mm coated titanium rod as primary anode. The electrical connection to the concrete was established with a graphite paste. As feeder wire a titanium wire welded to the primary anode was used. Most of these installations are still successfully operating and this gives the durAnode® a real life durability which is unparalleled with almost all other anode types and massively greater then other discrete anodes.The durAnode® has constantly been developed so that it has the following unique features;
- An optimal current output and distribution is established using a built-in resistor.
- All exposed parts are made of titanium to ensure high durability.
- A mechanical connection system of the feeder wire ensures a quick and durable connection.
Today the durAnode® system also includes the durAnode®3 which uses a special developed grout that connects the primary anode to the concrete. This special grout gives the durAnode®3 a very good performance in dry concrete or masonry. The primary anode is micromesh folded to form a ø7-8mm tube. Using the micromesh the electrical conductance between primary anode and backfill is improved compared to a massive rod. Also as there is mortar on the inside of the tube the amount of buffering capacity of the grout is effectively doubled.
The output of the anodes must be adjusted to the need for cathodic protection. This is done by using a built-in resistor in each anode. This resistor combined with the relatively small size of the anode area prevents major differences in current output. This allows a higher average current density than for a system with large anodes and no pre-resistors.Disadvantages
- Sometimes the durAnode® system can be difficult to place when there is a large and randomly placed reinforcement in a structure.
- The durAnode® system is not cost effective when there are thin sections of structure.
- The durAnode® system can be installed using few tools: cover meter, hammer drill.
- The durAnode® system does not increase the weight and dimension of the structure. This is of particular importance in car parks where the height is very limited and on some type of bridges.
- The durAnode® system can be completely hidden. Thus it can be used in historic buildings to protect steel girders. Below is a picture of the corrosion on 70m2 slab. The yellow spots are areas with high corrosion rate. The durAnode® can be used for hot spot protection. The durAnode® system was installed in these areas only. In this way the costs was reduced without reducing the protection levels.
- The durAnode® installation is unlikely to go wrong as can happen with other anode types.
- The durAnode®s in built resistor means that inadvertent short circuits can be tolerated between the anode and cathode without having to completely refurbish the zone.