A comperative study of ground probing radar and impact echo nodestructive techniques for detecting and locating buried objects
M. Momayez, A. Sadri and F.P. Hassani
Event name: Fifth International Conferention on Ground Penetrating Radar
Session: Pavement and Non-Destructive Testing (NDT)
Publication date: 12 June 1994
Info: Extended abstract, PDF ( 907.1Kb )
Price: € 20
The comparison of two nondestructive testing methods for detecting flaws and locating buried objects in concrete is the focus of this paper. Applications of Ground Probing Radar (GPR) and Impact Echo (IE) techniques are examined. In addition, this investigation shows thatwhen GPR and IE are used in tandem, extensive information about the integrity of concrete can be obtained in a short period of time. GPR is an electromagnetic reflection technique utilizing nonionized microwaves whereas IE makes use of transient stress wave reflections. Although both techniques are based on wave reflection, the nature of the information carried in the reflection signals from GPR and IE is different and complimentary when combined together. In this study, a large concrete slab was prepared with various types of objects such as rebars, metal and plexiglass plates, rocks and thin plastic sheets simulating cracks placed in it. It is shown that GPR can be used to detect flaws and buried objects rapidly while IE can locate flaws and buried objects accurately and provide reliable data on the mechanical properties of concrete. The combined use of Ground Probing Radar and Impact Echo techniques is an effective tool for concrete monitoring and quality control.