Surveying the layers of pavement using ground-penetrating radar

Multi-channel GPR with ground coupled antennas can acquire underground records with little amount of multiple reflections. We use multi-channel GPR equipment, which can scan at high speed on a paved road, to acquire underground survey records at a test road which has many sections composed of different type of materials and depths. The records clearly indicate horizontal boundaries of road construction without processing of background removal. We acquired zero-offset profiles applying normal moveout (NMO) correction for GPR records. NMO correction is useful to detect the shallow boundary below asphalt concreate mixture. GPR with bow-tie antenna of ground coupled type, which can scan on paved road at high speed has high potential to monitor the condition of road construction.