Non-destructive Testing (NDT), Improving investigation cost value.
​Failure analysis on existing structures can sometimes involve many assumptions being made relating to the existing building materials and soil conditions.
These assumptions may not accurately reflect the actual conditions or parameters of the structure. In turn, these assumptions can potentially lead to incorrect conclusions relating to structural rectifications, ultimately resulting in the client spending unnecessarily.
Through structural testing instruments, engineers can become more certain with their initial assumptions, which results in an improvement in the accuracy of their conclusions and recommendations.
The two types of structural testing methods available to engineers includes “destructive and non-destructive testing (NDT)”. Destructive testing involves physically damaging the structure for the purpose of collecting a sample for further analysis.
Typically, heavy machinery is associated with this DT (destructive testing) method of testing which triggers, site safety hazards, noise pollution, weakening of the already impaired structure, and immediate rectification.
NDT (non-destructive testing) testing is typically carried out in a faster, quieter, safer and cost effective fashion, allowing the engineer to retrieve similar information to DT testing.
A basic comparison of DT vs NDT testing would be a concrete compressive strength test. The NDT test would involve the use of a handheld Schmidt hammer, a device designed to approximate the surface hardness of materials/concrete. This test is timely, completed and providing results within ten seconds without damaging the structure or eliciting any safety concerns.
The alternative DT test would involve coring the concrete/material with heavy loud drill, then sending the samples to a specialised lab for compression testing.
There are instances where DT testing can trump NDT testing in providing more accurate information relating to building materials, although the excess information may be irrelevant to the specific project.
Overall, non-destructive testing (NDT), provides high value to engineers and clients. It ensures that less assumptions are made relating to the existing structural conditions, which improves the accuracy of findings and drives down the overall cost on rectifications, eliminating any unnecessary rectifications.