Near-Field Microwave Techniques for Detecting Stress-Induced Cracks in Cement-Based Materials


Concrete columns are subjected to minor to medium damage at plastic hinges during an earthquake event. In such a case, it is desirable to determine the residual strength of steel reinforcement that is still covered with cracked concrete. The mapping of surface cracks on the surface of a concrete column may yield useful information for this purpose. Consequently, near-field microwave nondestructive evaluation (NDE) methods are used to detect flexural cracks and evaluate their width, extent, and spatial distribution on columns. This paper presents the viability of using open-ended rectangular waveguide probes for detecting interior and surface cracks in mortar and concrete samples. The results of scanning cylindrical samples possessing simulated interior and surface-breaking cracks using a microwave reflectometer at several microwave frequencies is presented. In addition, the influence of various parameters on crack detection is discussed.

Meeting Name

1st International Conference on Structural Health Monitoring and Intelligent Infrastructure (2003: Nov. 13-15, Tokyo, Japan)


Electrical and Computer Engineering

Second Department

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Cement Based Material; Concrete Column; Concrete Samples; Cracked Concretes; Cylindrical Samples; Earthquake Events; Flexural Cracks; Microwave Reflectometers; Microwave Technique; Near-Field; Non-Destructive Evaluation Methods; Plastic Hinges; Residual Strength; Steel Reinforcements; Stress-Induced; Surface Cracks; Surface-Breaking Crack; Concrete Construction; Damage Detection; Rectangular Waveguides; Surface Defects; Crack Detection

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2003 CRC Press, All rights reserved.

Publication Date

01 Nov 2003

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