Corrosion is an electrochemical process that damages and even destroys metal. Bridges, most of which contain hundreds of thousands of metal components, are exposed to the elements and thus particularly vulnerable to corrosion. The utilities attached to bridges, often housed in special pipes, are also susceptible to corrosion over time.
Prevention is key since replacing corroded pipes is far more costly and time-consuming than maintenance. How can bridge utility piping avoid corrosion? Here are three ways to keep corrosion at bay on bridge utilities.
- Control for moisture.
Most bridge utility corrosion is localized meaning the metal loss is concentrated in one specific area. Crevice corrosion is hyper-localized in corners and cracks where moisture is able to stagnate. Gaskets, bolts, rivets, and lap joints present prime conditions for this kind of corrosion, especially in high-humidity areas. To prevent corroding of metal components in high-moisture environments it’s best to use non-corrosive materials. Steel piping and, more specifically, metal hanger systems used on all kinds of pipes including PVC, fiberglass, and plastic, should be inspected regularly and considered for replacement by materials such as hot dipped galvanized and stainless steel.
- Install utility piping in well-ventilated areas.
One of the easiest ways to avoid moisture build-up is to install utility pipes and their hanger systems where they are exposed to plenty of air. Not only will excess precipitation drain better when utility pipes are attached at elevated points, air will more freely move around them allowing crevices to dry thoroughly between periods of high moisture. Conversely, moisture conditions (as well as chloride ions) present in soil can contribute to further corrosive build-up. Installing pipes away from soil can add longevity to their lifespan.
- Utilize barrier coatings.
Barrier coatings keep corrosion from reaching the vulnerable steel below. The general practice of applying a zinc primer over properly-prepped steel is a proven way to prevent corrosion from forming. Top coats must be tested for chalking, the effect of UV lights, and moisture control. Like barrier coatings, galvanizing – the application of zinc metal to steel – protects the underlying metal from corrosion by taking on the effects of corrosion itself. Hot-dip galvanizing is considered the most effective way to prevent corrosion on unusually-shaped parts such as those used in hanger systems. Anti-corrosive wax tape is also a useful, cost-effective way to prevent the effects of corrosion when pipes are wrapped completely.
Aptus specializes in maintaining and protecting bridge-attached utilities. Are you worried about corrosion affecting your bridge utility project?
Contact our team today to take the necessary steps to protect your structure.