Application of electromagnetic waves in damage detection of concrete structures

Maria Q. Feng, Franco De Flaviis, Yoo Jin Kim, Rudy Diaz

Research output: Contribution to journalConference articlepeer-review

8 Scopus citations


Jacketing technology using fiber reinforced polymer (FRP) composites is being applied for seismic retrofit of reinforced concrete (RC) columns designed and constructed under older specifications. In this study, the authors develop an electromagnetic (EM) imaging technology for detecting voids and debonding between the jacket and the column, which may significantly weaken the structural performance of the column otherwise attainable by jacketing. This technology is based on the reflection analysis of a continuous EM wave sent toward and reflected from layered FRP-adhesive-concrete medium: Poor bonding conditions including voids and debonding will generate air gaps which produce additional reflections of the EM wave. In this study, dielectric properties of various materials involved in the FRP-jacketed RC column were first measured. Second, the measured properties were used for a computer simulation of the proposed EM imaging technology. The simulation demonstrated the difficulty in detecting imperfect bonding conditions by using plane waves, as the scattering contribution from the voids and debonding is very small compared to that from the jacketed column. Third, in order to alleviate this difficulty, a special dielectric lens was designed and fabricated to focus the EM wave on the bonding interface. Furthermore, the time gating technique is used in order to reduce the noise resulting from various uncertainties associated with the jacketed columns. Finally, three concrete columns were constructed and wrapped with glass-FRP jackets with various voids and debonding condition artificially introduced in the bonding interface. Using the proposed EM imaging technology with the lens especially designed and installed, these voids and debonding condition were successfully detected.

Original languageEnglish (US)
Pages (from-to)118-126
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Jan 1 2000
Externally publishedYes
EventSmart Structures and Materials 2000: Smart Systems for Bridges, Structures, and Highways - Newport Beach, CA, USA
Duration: Mar 6 2000Mar 7 2000

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Application of electromagnetic waves in damage detection of concrete structures'. Together they form a unique fingerprint.

Cite this