Non-destructive testing of civil structures 

Reflecting on recent launch of CIRIA's C798 guidance Chris Atkins, Technical Principal, Mott MacDonald and co-author of this guide provides an overview.

When you are trying to look after infrastructure, there’s a lot of information that would be really good to know. What’s it made of? How strong is it? How thick is it? Is there anything wrong with it? Is anything bad happening? When will I need to spend money on it? 

There are simple ways of finding any of this out with 100% confidence. You can take it apart, crush or stretch bits until they break, and look at the left-over bits under a microscope, but instead of a nice shiny thing, you end up with a pile of rubble, which limits the use of your infrastructure. What you need to do is find out all the information over enough of the structure to feel confident, without destroying it in the process. You need non-destructive testing or evaluation (NDT or NDE). You might be able to use minimally destructive testing (MDT) in some areas. 

There is a lot of information available about a wide range of techniques that can be used to investigate structures, without destroying them in the process. C798 from CIRIA provides a guide through the techniques currently available, with the aim of helping to increase the appropriate use of NDT on civil engineering structures.

The guide provides an overview of the techniques available, then incorporates illustrations of what you may want to use on different structure types and materials. A handy section is also provided on carrying out NDT works, including the need to have someone trained and competent using the equipment and interpreting the data. There are also some thoughts on the future for NDT.  The appendices also contain examples of the techniques beings used, and a summary sheet of techniques currently in common usage. 

The guide is available to order from CIRIA: https://www.ciria.org/c798