Nondestructive testing of concrete using highly nonlinear solitary waves

Abstract

In this article, we describe the capability of a nondestructive evaluation (NDE) method at determining the strength of concrete surfaces. The method uses highly non-linear solitary waves (HNSWs) propagating inside a metamaterial in contact with the concrete to be tested. The metamaterial consists of a chain of spherical particles, and is part of a built-in transducer designed to excite and detect HNSWs. The NDE method exploits the dynamic interaction between the metamaterial and the concrete, and the hypothesis is that this interaction depends on the stiffness of the specimen being inspected. In this study, we tested this hypothesis by assembling two kinds of transducer and by casting cylinders with different water-to-cement ratios. The results show that the time of flight of the HNSWs is inversely proportional to the modulus of elasticity of the concrete. Once fully developed, the proposed NDE method may easily assess concrete surfaces.

Keywords:

• Nondestructive evaluation
• highly non-linear solitary waves
• concrete
• magnetostrictive sensors
• ultrasonic pulse velocity method

Acknowledgements

The use of the results or reliance on the material presented is the responsibility of the reader. The contents of this document are not meant to represent standards and are not intended for use as a reference in specifications, contracts, regulations, statutes or any other legal document. The opinions and interpretations expressed are those of the authors and other duly referenced sources. The views and findings reported herein are solely those of the writers and not necessarily those of the US Department of Transportation, Federal Highway Administration or the Commonwealth of Pennsylvania. This paper does not constitute a standard, a specification or regulations.