Masters Theses


"The objective of the investigation has been to determine non-uniform dielectric property profile in a mortar sample using microwave nondestructive testing techniques. For this purpose, mortar samples with specific cross-sectional dimensions were produced. These samples were then exposed to saltwater solution and subsequently oven-dried. This exposure procedure produced a non-uniform distribution of salt and uniform moisture distribution throughout the sample length. Subsequently, calibrated microwave reflection and transmission property measurements were performed using an HP8753E vector network analyzer in conjunction with a two-port completely-filled waveguide measurement technique. The measurement results clearly showed that this measurement technique employed was capable of detecting cyclical ingress of salt as a function of cycles. To understand these measurements an electromagnetic model was developed as well. Given the dielectric property profile (as a function of length) of a dielectric material, the model computes the microwave reflection and transmission properties of the material when it is enclosed in a rectangular waveguide. To determine the dielectric property profile.of the samples an iterative back-calculation model was developed. The inputs to this model are the effective dielectric properties and the measured reflection and transmission properties of a given sample. The calculated dielectric property profiles can then be used to compute the sought after gradient of salt ingress (i.e., solid products) in the sample using a dielectric mixing model. This thesis presents a detailed description of the measurement technique and the results and the step-by-step development of the electromagnetic models"--Abstract, p. x


Dr, Reza Zoughi

Committee Member(s)

Dr. Todd Hubing
Dr. Abdeldjelil Belarbi


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


University of Missouri--Rolla

Publication Date

Spring 2004


xix, 163 pages

Note about bibliography

includes bibliographical references (pages 160-162)


© 2004 Bharath Kumar Akuthota, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Nondestructive testing
Concrete -- Permeability
Chlorides -- Permeability

Thesis Number

T 8380

Print OCLC #


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