CORROSION IS NATURAL, BUT THAT DOESN’T MEAN YOU CAN’T SLOW OR PREVENT IT
BY GARY SEIDER
For many, corrosion may seem like a minor problem. A little rust here and there, maybe some pipes weaken and need to be replaced down the road — nothing that can’t be handled. And on a case-by-case basis, this may be true, because sometimes all corrosion amounts to is a little rust.
But even those who know better, who recognize how unchecked corrosion can lead to serious structural failure like a collapsed bridge, may not realize just how high the overall cost of decomposition is. On an annual basis, the global cost of corrosion is more than $2 trillion, with half of that coming from the U.S. alone.
Corrosion is a far-reaching problem — it’s costly in terms of money, public health and safety. And for those in the construction industry, it’s an issue that has to be taken very seriously.
THE ROOT OF THE PROBLEM
But why is corrosion such a pervasive problem? And, more important, how did it become one of the biggest drains on the U.S. economy? The simple answer is that most environments are made to corrode.
Something as simple as soil’s high oxygen levels significantly speeds up deterioration. The presence of water, too, is a major factor, and unless you’re building in a desert, it’s nearly impossible to keep water away from a structure indefinitely or to completely waterproof metal. Even the tiniest damage in a protective coating leaves a structure vulnerable to corrosion.
And, somewhat counterintuitively, because corrosion happens so often, many people don’t even look at it as preventable — metal will eventually corrode and need to be replaced. After all, it’s one thing to know that clay soil tends to trap water longer, increasing the chance of corrosion. If you’re building on clay soil, then there’s not much that can be done about it, right?
To a certain degree, that may be true, but while corrosion can’t be stopped 100 percent of the time, there are management techniques that can noticeably stunt its growth and — in many cases — even prevent it from spreading altogether.
START ASKING THESE QUESTIONS TO STALL CORROSION
Just because it’s a part of nature’s course doesn’t mean architects and contractors are helpless against corrosion. There are three simple questions you can ask yourself to help you manage corrosive elements in the environment and save your construction company a significant amount of money and heartache:
1. What metals are being used?
Currently, most metals are chosen on the basis of their physical and mechanical features. Meanwhile, chemical makeup — a major factor in a metal’s vulnerability to corrosion — gets largely overlooked.
Depending on the environment these metals are in, this can be a costly mistake, and it’s why the corrosion control industry is in the midst of two decades of rapid growth. Carefully consider all three qualities of a metal — physical, mechanical and chemical — when choosing the best materials for long-term durability.
2. What’s the makeup of the soil? The speed and severity of corrosion leans heavily on the composition of the soil it’s in. Depending on its composition, the effects of the soil could be negligible, or it could spur on corrosion at a rapid pace.
A number of factors can make soil more or less corrosive — such as the levels of oxygen, acidity and salt — but the No. 1 culprit is moisture. While a completely dry environment would be ideal, it’s not often an option.
Focus on minimizing the amount of moisture in the environment when possible, and be especially wary of flowing water, which lends itself more to corrosion than stagnant water.
3. Are you using the right coating, and is it properly applied? An excellent way to counteract environmental elements beyond your control is to coat your metals. But many coatings aren’t completely watertight because of either errors in application or natural pin holes in the material. These seemingly insignificant exposures can lead to serious corrosion.
While no coating is completely foolproof, asphaltic and galvanized coverages offer the most reliable, water-tight sealants. Should damage occur during installation or should the coating be inconsistent in places, there are methods to detect miniscule points of vulnerability before corrosion detects it for you.
Corrosion is a natural process — the environment wants to degrade and change the materials being placed within it. But just because it’s inevitable doesn’t mean you need to just stand back and watch it eat away at what you’ve built.
Take the necessary steps and ask these questions to keep a seemingly minor problem from becoming a major concern.
Gary L. Seider, P.E., is engineering manager of Hubbell/CHANCE® civil and utility helical products. Hubbell Power Systems manufactures a wide array of transmission, distribution, substation, OEM, and telecommunication products used by utilities. With four U.S. patents and more than 40 years of industry experience, Seider oversees the company’s civil construction and utility application/project engineering staff. His team assists owners, engineers, and contractors with technical assistance, guidance, and recommendations for the proper use of CHANCE helical anchors and piles and Atlas Resistance® products.