It is important to consider other holistic factors when making structural rust repairs. Such as moisture, salinity, chemicals, and electrolysis that can also contribute to the corrosion of steel and other metals.
Moisture: The presence of water or moisture can accelerate the corrosion of steel and other metals. Water can dissolve many of the compounds that form on the surface of metal and carry them away, exposing the metal to further corrosion.
Salinity: Saltwater is particularly corrosive to metals, especially steel. The salt in the water can dissolve and carry away metal ions, leading to corrosion.
Chemicals: Certain chemicals can also be corrosive to metals, particularly if they are acidic or basic. These chemicals can attack the surface of the metal, leading to corrosion.
Electrolysis: This type of corrosion occurs when two different types of metal are in contact with each other in the presence of an electrolyte (such as water or a salt solution). An electrical current can flow between the two metals, causing one of them to corrode.
Use non-conductive materials to separate different types of metal: If it is necessary to use different types of metal in close proximity to each other, it is important to use non-conductive materials, such as rubber or plastic, to separate them. This will prevent an electrical current from flowing between the metals and causing corrosion.
Cathodic protection: This is a method of protecting metal surfaces from corrosion by using an electrical current to prevent the corrosion reaction from occurring. It is often used to protect metal structures, such as pipelines, tanks, and ships, from corrosion.
There are two main types of cathodic protection: galvanic cathodic protection and impressed current cathodic protection.
Galvanic cathodic protection: This method involves attaching a more electrically active metal, such as zinc or aluminum, to the surface of the metal that is being protected. The more electrically active metal will corrode instead of the less active metal, protecting it from corrosion.
Impressed current cathodic protection: This method involves running an electrical current through the metal surface that is being protected. The current helps to neutralize the corrosion reaction, protecting the metal from further corrosion.
Cathodic protection can be an effective way to prevent corrosion in metal structures. However, it is important to design and maintain the cathodic protection system correctly in order to ensure its effectiveness. For this reason specialist contractors provide these Design and Construct services, and can offer a maintenance schedule with regular intervals to ensure that the system is functioning properly.
To prevent corrosion, it is important to protect metal surfaces from exposure to water, salt, and chemicals, and to use corrosion-resistant materials whenever possible. In addition, it is important to regularly inspect metal surfaces for signs of corrosion and to repair any corrosion that is found as soon as possible.
Regular inspections especially on coastal bridges, culverts and buildings is a good place to start, ideally from an RPEQ Engineer.