Location

Portland State University

Start Date

7-5-2019 11:00 AM

End Date

7-5-2019 1:00 PM

Subjects

Reinforced concrete -- Diagnostic imaging, Ground penetrating radar, Nondestructive testing, Machine learning, Ultrasonic imaging

Abstract

Structural concrete is the most widely used construction material in the world. Many structures critical to a society such as bridges, hospitals, and airports are built with concrete. While this material is well understood from a mechanical design point of view, still no accurate quantitative tools exist to assess it for damage and deterioration. This is of particular concern for an urban area like Portland with a mega-thrust earthquake waiting to occur. Non-destructive evaluation tools that can quickly and accurately give a full picture of the integrity of structural concrete elements will be key to help plan effective and safe recovery missions.

Ground penetrating radar is a non-destructive testing device which uses electromagnetic waves to assess the interior of the concrete and is especially useful in identifying embedded rebars in the concrete. In addition, ultrasonic array is a tool which uses stress waves and their echoes to image inside the concrete. This technique is most useful where there is a concrete and air interface.

In this research, signals from both modalities are obtained from the specimens built in the iSTAR laboratory. Further, the signals are processed to generate a visual representation of the interior of the concrete. Finally, a high resolution image is obtained by data fusion of the two different modalities. The results show a good approximation of the details such as the location of the rebars, air void and the depth of the concrete.

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May 7th, 11:00 AM May 7th, 1:00 PM

Diagnostic Imaging of Structural Concrete Using Ground Penetrating Radar and Ultrasonic Array

Portland State University

Structural concrete is the most widely used construction material in the world. Many structures critical to a society such as bridges, hospitals, and airports are built with concrete. While this material is well understood from a mechanical design point of view, still no accurate quantitative tools exist to assess it for damage and deterioration. This is of particular concern for an urban area like Portland with a mega-thrust earthquake waiting to occur. Non-destructive evaluation tools that can quickly and accurately give a full picture of the integrity of structural concrete elements will be key to help plan effective and safe recovery missions.

Ground penetrating radar is a non-destructive testing device which uses electromagnetic waves to assess the interior of the concrete and is especially useful in identifying embedded rebars in the concrete. In addition, ultrasonic array is a tool which uses stress waves and their echoes to image inside the concrete. This technique is most useful where there is a concrete and air interface.

In this research, signals from both modalities are obtained from the specimens built in the iSTAR laboratory. Further, the signals are processed to generate a visual representation of the interior of the concrete. Finally, a high resolution image is obtained by data fusion of the two different modalities. The results show a good approximation of the details such as the location of the rebars, air void and the depth of the concrete.