Abstract :
The goal of the present study is to employ ground penetrating radar (GPR) to measure the performance of geotextiles used in pavement systems. A common function of geotextiles in pavements is to provide separation between the distinct layers of subbase and subgrade, and thus prevent the fmer soil material found in the subgrade from migrating to the subbase layer. Geotextiles have an ability to withstand tear, puncture, and the grabbing effect of soil movement, and their perfmmance depends on factors such as the fabric stiffness, creep and anchorage as well as the type, shape and frictional characteristics of the surrounding aggregates. Geoctextile performance is expressed in terms of the fabric?????????s ability to continue to keep the surrounding soil materials separated. Deterioration in performance is due to intrusion of soil through the geotextile from one layer to another, and is captured as change in intensity of the reflected EM wave at the interface of the two layers. GPFL surveys are conducted on a roadway located in upstate New Yorlk, which serves as a testbed for evaluating the performance of vari~ous woven and non-woven geotextile materials. The generated GPR images were processed and interpreted to determine the performance of the geotextile present in each section. The measures obtained are the thickness of each pavement layer and the reflection amplitude at the layer interfaces. Examinations of the contour maps of the reflection amplitudes provided the information needed to characterize the performance of each geotextile material in terms of its ability to separate the surrounding layers. The text presents the findings of the study in the form of a series of contour maps and tables listing key statistical parameters of the measured quantities. The conducted analysis and results of this study are presented and discussed, together with a number of important findings. It is concluded that for the conditions examined in this study, GPR can detect the infi- tration of finer materials across the layer interface, and, thus, enable a determination of geotextile performance.
