Moisture influence on the GPR-measured RDP values of granite ballast under clean and fouled conditions

Abstract

Ground Penetrating Radar (GPR) has recently been a routine non-destructive tool in railway infrastructure diagnostics. One of the phenomena occurring in the ballast structure, which can be detected by GPR, is presence of water. Moisture (water) can be trapped more frequently in the fouled railway ballast sections due to the filling of air voids within the ballast by finer materials hence reducing the drainage capability of the track infrastructure. This paper aims at experimentally assessing the moisture influence of the clean and fouled coarse granite ballast on the GPR signal characteristics.