In the U.S. alone, the construction industry creates around $1.3 trillion worth of structures every year, and employs around 7 million people. We spend much of our lives surrounded by the fruits of this labor, usually without thinking about what it takes to produce, and without a real awareness of how much we rely on those structures to be safe. We rarely enter buildings worrying that they are going to collapse, for example, or drive across a bridge fearful that it will crumble beneath our tires. That safety and public trust is important to maintain, and as the numbers of structures increase every year, that means regular inspection of more and more structures every year. A large number of the structures build rely upon concrete either in part or for the vast majority of their construction.