A Study On The Application Of Ground Penetrating Radar In Highway

With the great development of highway construction in the China, pavement investment has occupied a big part of road and highway investment since the reform and open-up, at the same time, pavement quality affects the total quality of highway, and pavement usage life span directly has an effect on the investment benefit and the quality of highway. The original testing method of project quality, which is obtained by taking pavement core samples, is a slow, low-efficient, poor-representative and destructive task, thus it is necessary to develop a quick, simple, efficient and nondestructive testing method of pavement quality. In road structure surveys, GPR has been used to measure layer thickness, to detect voids under concrete skbs, to evaluate the density and water content of subsurface kyers of the pavement In fact, GPR, which is a quick, high-precision, non-touching and nondestructive testing tool, and which directly gains subsurface section images and carries on real-time imaging disposal of testing data, has a wide application foreground GPR has been caught the attention of a lot of countries; many universities and research institutions have introduced into the foreign GPR equipments, carried out some work and gained some fruits.In this paper, a systematical study was done for the engineering problem using GPR to evaluate pavement structure. The results are as follows:!) A detailed narration is concerned about GPR's makeup and exploration theory, 2) There is a qualitative analysis and a summarization about subterranean reflected signals according to the basic theories of electromagnetic, based on the dielectric characteristics of common subterranean medias; 3) GPR has a wide range of applications on roads and highways, in this introduction about subgrade surveys and site investigations, damage surveys in road structures, and evaluating water content and compactness with detailed cases has been done. 4) attentions have focused on measuring the thickness of the concrete kyer on flexible and rigid pavements with air-kunched hom antennas; and 5) The formation of voids beneath concrete pavements is a serious problem. GPR can detect voids under concrete skbs. It is based on the identification of the amplitude of reflection of the skb/CTB interface. Some examples are offered to validate its application.Henan Engineering Research Center for Road NOT Technology (Zhengzhou University) recently has introduced a set of GPR systems produced by Pulse Radar inc in America; these systems have been used for thickness measurements and void identifications. To this day, Henan NDT center has earned out a lot of work This paper also emphasizes the two aspects.