Microwave Materials Characterization and Imaging for Structural Health Monitoring
This FREE webinar is hosted by the INSPIRE University Transportation Center, and presented by Dr. Reza Zoughi, Schlumberger Endowed Professor in the Electrical and Computer Engineering Department, and Director of the Applied Microwave Nondestructive Testing Laboratory (amntl) at Missouri S&T.
The relatively small wavelengths and large bandwidths associated with microwave signals make them great candidates for inspection of construction materials and structures, and for materials characterization and imaging. Signals at these frequencies readily penetrate inside of dielectric materials and composites and interact with their materials characteristics and inner structures. Water molecule is dipolar and possesses a relatively large complex dielectric constant, which is also highly sensitive to the presence of ions that increase its electrical conductivity. Consequently, chemical and physical changes in construction materials affect their complex dielectric constant. This can be measured, and through analytical and empirical dielectric mixing formulae, correlated to those changes. Examples of applications would be, presence of delamination in a bridge deck and pavement, permeation of moisture behind retaining walls or corrosion of reinforcing steel bars which can be imaged with microwave techniques. One of the critical trade-off issues is between the microwave signal penetration into concrete vs. frequency of operation. Dielectric of concrete, particularly when moist, has a relatively high loss factor. As such, lower microwave frequencies are suitable to achieve reasonable penetration. Image resolution degrades as a function of decrease in operating frequency, therefore, a balance must be reached when using these techniques for imaging cement-based materials. In this webinar, issues related to concrete materials property evaluation and high-resolution imaging will be discussed, and examples will be provided.
Thursday, March 15 at 11:00am to 12:00pm
Missouri S&T Campus, or Attend Online, 209 Computer Science Building REGISTER HERE: https://zoom.us/meeting/register/5edd93691d290b6666858a512be5123a