Nondestructive Testing in Asphalt Pavements Using Ground Penetrating Radar (GPR)

Abstract

This paper presents the results of using the system GPR (Ground Penetrating Radar), as an alternative that uses radio waves at frequencies from 10 to 2500 MHz to get data that enable non-destructive conduct inspections of underground or concrete structures in real time. The research aims to investigate asphalt pavements, analyzing the variations in the responses, which can reveal the presence of pathologies or defects. A case study was made acquiring data, at the State University of Campinas - UNICAMP, in Campinas – SP – Brazil, with antennae 270 and 1600 MHz, in pavements with visible defects of patching and alligator cracks, initially with the dry structure and later, wet. The results were processed in specialized software (Radan 7.0) to generate terrain profiles. The GPR showed effective when there is a change in material employed as in the case of patching, because it was possible to detect layers compromised by intensive request of traffic, the start and end of application of the patching and even deformations in the new layer. In contrast, the alligator cracking did not reach the same result, not presenting accuracy in recognizing the defect. The extent of defect was the only well defined feature in the images.