Background
Coring of bridge deck with post-tension cables required for condition assessment.
Methodology
Ground Penetrating Radar (GPR) used to locate depth and lateral position of all post-tension cables and rebar. Initial large scale survey performed to locate all targets on deck. The initial survey was performed with the SmartCart and 103m x 8m grid with 0.5m line spacing. Follow up surveys performed at time of coring to clear areas for cores.
Findings
Figure 1 is a plan view drawing displaying embedded rebar in a concrete slab; processed depth slice between 0.10 – 0.30m. Bright spots at 43m and 60m correspond to the apex of post-tensioned cabling.
Figure 2 is a processed radar section through a post-tensioned slab, displaying reflections from transverse and longitudinal post-tension cables and regular rebar.
