IMPULSE RADAR REFLECTION WAVE-FORMS OF SIMULATED REINFORCED-CONCRETE BRIDGE DECKS

This paper presents the findings of an experimental study on the use o f ground penetrating radar (GPR) for nondestructive evaluation of rein forced concrete bridge decks. An impulse radar PS-24 system was used f or this study Fifteen concrete bridge deck specimens were cast in thre e batches. The internal conditions were varied as follows: with steel reinforcement and unreinforced, with air cracks, with plain water-fill ed cracks, and with saline water-filled cracks. These specimens were t ested using the impulse radar; the radar waveforms and color intensity plots of the radar amplitude were then studied. The individual radar waveforms from the specimens with varying internal conditions were com pared to determine the effect of subsurface defects. The results show that the impulse radar can identify and locate the internal delaminati on, especially when filled with water, and can correctly determine the location of embedded reinforcing steel.