Georadar GSSI and 3DR
Mobile GPR systems allow a detailed assessment of the structure under study, both in quantitative and qualitative terms. With georadar application, in addition to measuring the thickness of layers, more advanced tasks can be performed, such as identifying the moisture content of pavement structures, characterizing the type and condition of interlaminar joints, identifying and investigating cracks, assessing the electrical susceptibility of layers, identifying the level of the ground water table and frost level, locating voids in concrete pavements, locating conduits and culverts, or assessing the degree of corrosion of reinforcement.
The GPR measurement technique uses the principles of electromagnetic wave propagation. When an electromagnetic wave penetrates the boundary of two layers with different dielectric properties, part of it is reflected, while the rest passes to the next layer and also undergoes refraction. The reflection phenomenon is the basis of the most common GPR measurement method called reflection. Refractive methods, geared toward measuring the time of a wave passage through the medium and estimating the wave velocity through that path, are used far less frequently, as they involve the need to place antennas inside the medium or use antenna arrays with spacing between them.