Non-destructive testing of reinforced concrete structures of bridge structures using GPR allows you to quickly obtain information about the technical condition of the object under study. Application of the GEORADAR-EXPERT software system significantly improves the quality of this information. The figure below shows a diagram of the study of a bridge column by a GPR with a central frequency of 300 MHz. GPR profiles were located opposite each other and had the same direction from bottom to top:
Based on the results of the automated analysis of the backscattered field (BSEF), sections of the attributes 'real part of the complex relative permittivity' and Q-factor (the ratio of the center frequency to the width of the spectrum of the reflected GPR signals) were created.
The permittivity sections:
The figure below shows the overlay of the image of the bridge column on the sections of permittivity, which are turned vertically and aligned so as to make a these sections passing through the position of the GPR profiles:
The sections of the permittivity can be seen that the bridge column is heterogeneous in its electrophysical characteristics. The values of the permittivity of this concrete bridge column lie in the range 5.4 - 8.1. The lowest permittivity values on the section are located closer to the center of the cross section (red-yellow colors of the section), and higher ones (blue shades of the section) are closer to the edges, i.e. closer to the surface of the column. First of all, the influence on the permittivity is exerted by the humidity of the studied object. The higher the humidity, the higher the permittivity.
The figure below shows a similar the overlay of the sections of Q-factor on image of the bridge column. The highest values of the Q-factor attribute on the sections are displayed in red and correspond to the areas of the least durable concrete. Yellow color corresponds to the concrete of low strength, blue color matches areas of normal strength concrete.
As you can see, using the automated analysis of the backscattered field, implemented in the GEORADAR-EXPERT software system, it is possible to effectively carry out non-destructive testing of the state of concrete support structures. A distinctive feature of non-destructive testing using GEORADAR-EXPERT is a high level of detail and clarity of the result obtained, as well as a relatively short time spent on processing GPR data.