Distributed Strain Measurement of a Large-Scale Reinforced Concrete Beam-Column Assembly under Cyclic Loading


In this paper, comparisons are made between the performances of two kinds of distributed sensors, Electric Time Domain Reflectometry (ETDR) cable sensor that is based on the propagation of electromagnetic waves in an electrical cable and Brillouin Optical Time Domain Reflectometry (BOTDR) optical sensor that is based on the propagation of optic pulses and Brillouin scattering that occurs when light is transmitted through the optic fiber. A cable sensor was mounted near the surface of the 80% scale beam-column reinforced concrete assembly that was loaded cyclically until the shear failure occurred. The embedded depth was 0.5 inches. At the same time, a fiber optic sensor was mounted on the surface of the assembly with two installation procedures called Point Fixation (PF) Method and Overall Bonding (OB) Method to measure the strain distribution. Both BOTDR and ETDR sensors were subjected to tension and compression in one loading cycle. Strain distributions obtained from the ETDR and BOTDR sensing systems under different cycle loadings were compared with each other. They were also compared with those measured from the traditional strain gauge.

Meeting Name

Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems (2005: Mar. 7-10, San Diego, CA)


Civil, Architectural and Environmental Engineering

Second Department

Electrical and Computer Engineering

Keywords and Phrases

Cyclic Loads; Electromagnetic Waves; Optical Fibers; Reflectometers; Reinforced Concrete; Sensors; Tensile Testing; Time Domain Analysis; BOTDR; Crack Sensors; Distributed Sensing; ETDR; Optic Fiber Sensing; Reinforced Concrete; Strain Sensors

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2005 SPIE -- The International Society for Optical Engineering, All rights reserved.

Publication Date

03 Jun 2005