Ground-Penetrating Radar

Ground-penetrating radar is the primary technology TRSC uses to see inside concrete and masonry structures without cutting, coring, or breaking them open. GPR transmits high-frequency electromagnetic pulses into a structure and records the reflected signals from internal interfaces, reinforcement, voids, conduits, delamination planes, and moisture zones. The result is a real-time subsurface profile that reveals what is hidden beneath the surface.

For existing asset investigation, GPR is indispensable. When original drawings are missing, incomplete, or unreliable, which is the norm for the heritage and aged assets TRSC investigates, GPR provides the as-built structural information that every subsequent engineering decision depends on. At 12 Creek Street, GPR scanning of the facade confirmed reinforcement layout and cover depths that directly informed the chloride penetration analysis, ultimately demonstrating that the facade condition was significantly better than conservative assumptions suggested.

TRSC deploys both 2D line-scan and 3D area-scan GPR systems, selected based on the investigation objective. Higher frequency antennae (1600–2600 MHz) provide fine resolution for reinforcement mapping and cover depth measurement in the upper 300mm of concrete. Lower frequency antennae (400–900 MHz) penetrate deeper for void detection, slab thickness measurement, and locating post-tensioning tendons. Dual-frequency scanning is standard practice for structural investigations where both reinforcement detail and deeper structural features are required.

GPR scanning is non-destructive, non-invasive, and can be performed on occupied structures without disruption to building operations. It requires no radiation licensing (unlike X-ray methods), produces results in real-time on-site, and can cover large areas efficiently. These operational characteristics make GPR the first-choice investigation technology for most TRSC engagements.