Destructive Testing vs. Non-Destructive Testing: Which Method Is Best for Structural Components?

Component and material testing are crucial to ensuring a safe build. However, the choice between destructive vs. non-destructive testing methods isn’t always an obvious one. Choosing the ideal approach can be challenging because the best way forward varies depending on the use case.

When to Use Destructive Testing

In general, destructive testing methods are best when determining a material’s limits. This option is also helpful when gauging how components respond to destructive forces they may encounter, such as corrosion or extreme temperatures.

Understanding these limits is crucial, as 12% of construction defects come from material flaws. Similarly, rework from defective components accounts for up to 15% of project costs. Hard data on how much a structure can withstand before implementing it helps avoid such expenses.

When to Use Non-Destructive Testing

Non-destructive testing, by contrast, is best as a means of verifying a structure’s integrity and current condition. It’s also useful for inspecting materials with limited availability or high costs.

Material prices have risen by 41.6% since 2020, with many individual resources experiencing more dramatic cost increases. Amid this trend, many firms may be uncomfortable with the idea of destroying some assets to test their strength. Non-destructive testing is a potentially more cost-effective solution.

Destructive vs. Non-Destructive Testing for Common Materials

The choice between destructive and non-destructive testing methods is largely situational. It depends on many factors, including a project’s budget and resources. However, some common materials and components are generally a better fit for one over the other. Knowing these broad trends leads to more informed decision-making.

Concrete

Source: Photo by Bjørn-Magnus Kristiansen on Unsplash

Concrete is often an ideal candidate for destructive testing. As the world’s second most-consumed substance, it’s widely available, so high costs and rarity are not a concern.

Firms must also verify the absolute limits, given the concrete’s structural role, so non-destructive methods are not always conclusive enough. More specifically, compression testing is one of the best ways to inspect concrete. Compressive strength is one of this resource’s most crucial characteristics when upholding a structure, so it deserves the most attention.

Concrete does not bend or rust, so tensile and corrosion tests are irrelevant, and impact tests don’t simulate the most persistent real-world stresses it will face.

Steel

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Non-destructive testing is typically a better fit for steel components. While tensile or hardness tests can be valuable, a metal part’s weakest points often stem from welds or cooling, which may vary between pieces, so destructive methods may be counterproductive.

Radiographic testing (RT) is among the best non-destructive approaches for steel structures. RT can detect weld flaws, volumetric defects and other areas of concern that may not be visible to the naked eye. It also requires minimal surface penetration and is relatively easy to perform quickly on-site to maintain productivity.

Lumber (Timber)

Source: Photo by Patrick Robert Doyle on Unsplash

Wood products are also a good fit for non-destructive testing, but for different reasons. Softwood lumber has seen a 12.6% price increase in the past year, making it the fastest-rising cost of any construction material, so destructive methods aren’t economically ideal.

As a natural resource, wood also varies between every sample, requiring more frequent tests, which doesn’t work with destructive approaches.

Stress wave testing is the best specific non-destructive method for wood. It’s simple enough to perform on-site, requires no preparation and analyzes lumber along several qualities, including strength, stiffness and rot, all of which impact its structural integrity.

Use the Right Testing Method for Your Components

There’s no one answer to the question of destructive vs. non-destructive testing in construction. The optimal path depends on the material and structure in question, as well as how much time, money and equipment a firm can afford to spend on the analysis.

Learning which testing methods are generally preferable for varying situations can lead to faster, more reliable decisions. Once crews understand the basics, the optimal path forward becomes clearer.

About the Writer: Lou Farrell

Lou, a Senior Editor at Revolutionized, has specialized in covering topics of Manufacturing, Industry, and Technology for years. He loves getting to share what he knows with others, alongside fueling his passion for writing.