Doctoral Dissertations


Huimin Mu


"Coaxial cables are mainly composed of inner and outer conductors, and a dielectric layer in between. In this study they are proposed as continuous sensors for monitoring of civil infrastructures. Due to small deformation and minor cracks of engineering interest, coaxial cables have never been applied into reinforced concrete (RC) structures until the late 1990s. The state of the art in design of a cable sensor is to replace the polyethylene pipe of a commercial cable with a rubber tube as a dielectric layer to increase the cable’s sensitivity up to 10 times. In this dissertation a new design of prototype cable sensor is proposed. The new sensors not only respond to the cable’s elongation directly but, more significantly, to the topology change in the outer conductor associated with the cable elongation. The latter effect is first proposed and investigated in this study.

An analytical model of the proposed sensor design was developed in this study to establish the relation between the directly measurable quantities with design parameters. Four types of the sensors with various parameters were also numerically simulated to confirm the analytical results. Both analytical and numerical results were validated through experimentation. After having calibrated with the strain applied on them, the sensors were embedded into twelve RC beams to understand how sensitive they are to stressing and cracking in RC beams. The results from the flexural tests indicated that the sensitivity of the newly designed sensors is 50~100 times higher than that of commercial cables to the longitudinal elongation. The new sensors can be used to successfully detect both the location and width of a crack in RC members"--Abstract, page iii.


Chen, Genda

Committee Member(s)

Cheng, Franklin Y.
Belarbi, Abdeldjelil
LaBoube, Roger A.
Drewniak, James L.
Rao, Vittal S.


Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering


This study was supported in part by the U.S. National Science Foundation under Award No.CMS9733123 and No.CMS0200381, and by the Intelligent Systems Center at the University of Missouri--Rolla.

Research Center/Lab(s)

Intelligent Systems Center


University of Missouri--Rolla

Publication Date

Spring 2003


xiv, 164 pages

Note about bibliography

Includes bibliographical references (pages 157-163).


© 2003 Huimin Mu, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Subject Headings

Reinforced concrete construction
Coaxial cables
Smart materials

Thesis Number

T 8641

Print OCLC #


Link to Catalog Record

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