Review on microwave nondestructive testing techniques and its applications in concrete technology

•Various conventional and NDT tests of concrete are reviewed.•The MNDT techniques used in concrete applications are summarized.•MNDT techniques minimize processing time and preserve of energy.•The advantages of MNDT include instant measurements with monochromatic radiation.•The findings assist in the selection of suitable methods for concrete repair. Every year, a massive amount of literature is published on many aspects of microwave applications. Over the past few years, the need for progressive methods for assessing different properties of concrete, as well as for maintenance and monitoring of structures, has led to the development of microwave non-destructive testing (MNDT) techniques for preserving the civil infrastructure. MNDT has many advantages, including good penetrability in nonmetallic materials, instantaneous measurements, monochromatic radiation, low power requirements, substantial energy savings, and easy-to-interpret data. Additionally, with the potential to overcome the limits of both conventional testing and non-destructive testing (NDT), MNDT has received much interest. In this paper, a comprehensive review of the most common MNDT techniques for material assessment is conducted based on a detailed literature survey. Furthermore, the basics of MNDT techniques are explored to contribute to its use in the concrete industry. The conventional tests and NDTs on concrete, including the applications of different MNDT methods, are discussed. The outcomes of this review can assist in using the MNDT methods in concrete structures, structural health monitoring, and enhancement of microwave-based techniques. Finally, this work provides a summary of MNDT techniques used in concrete applications, which can lead to advancements in this field.