Structural
Integrity Assessment
Rebar mapping, voids, delamination, honeycombing and internal cracks. — using GPR and ultrasonic tomography.
Visualising Through
Concrete & Masonry
Reliable remediation of concrete structures depends on precise diagnosis and characterisation of defects — in particular the depth and lateral extent of both visible external and concealed issues such as voids, honeycombing, delamination, cracks, and inconsistencies within the matrix.
We employ multi-dimensional 2D/3D high-resolution imaging techniques via high-frequency ground-penetrating radar (GPR) and ultrasonic tomography. Advanced depth-slicing image processing can be applied to precisely identify, evaluate and measure the depth and lateral dimensions of each defect.
Testing conducted in alignment with AS/NZS 2425:2015, ASTM D6432, ASTM D6431–99(2010), and ASTM D6087–08(2015).
- Slab thickness measurement
- Reinforcement cover depth
- Rebar type & spacing
- Post-tension tendon location
- Utility and conduit mapping
- Voids and cavities
- Honeycombing and porosity
- Delamination layers
- Hidden internal cracks
- Corrosiion probability & rate
Air-filled or water-filled voids within the concrete matrix, beneath slabs, or behind walls. Detected as strong high-amplitude GPR reflections. Depth, extent and volume estimated from multi-directional scans.
Horizontal separation planes within concrete slabs or overlay systems — caused by differential thermal movement, corrosion-induced expansion, or poor bonding. C-scans reveal the plan extent of delaminated zones at specified depth.
In-situ compressive strength estimated through combined non-destructive testing. Rebound hammer measures surface hardness whilst UPV measures pulse velocity through the section — the SonReb correlation combines both to produce a reliable strength estimate without coring.
Vertical or inclined crack planes invisible from the surface — caused by overloading, settlement, or shrinkage. GPR diffraction patterns and UT velocity anomalies reveal crack depth and orientation.
Determine location and orientation of rebar and service conduits for cutting, coring & estimating slab load capabilities.
Oxidation of embedded steel causes volumetric expansion, cracking overlying concrete and creating delamination planes. GPR detects the resulting anomalies; confirmed by corrosion probability testing.
Ground Penetrating Radar
A high-frequency radar antenna is traversed across the surface, recording reflections from dielectric boundaries — reinforcement, voids, tendon ducts and slab soffits. B-scan profiles provide a real-time cross-section; multi-directional grids are compiled into C-scan plan views showing depth-sliced sub-surface maps of the entire scanned area.
| Application | |
|---|---|
| Rebar mapping and cover | Locate orientation and depth of concrete reinforcment |
| Post-Tension Cable | Characterises hyperbola diffraction to identify post-tensioning |
| Slab Thickness | Variation in material dielectric properties causes signal reflection at boundary |
| Voids | Highlight bands within radargram to determine void location and depth. |
Ultrasonic Pulse Velocity
A transmitting transducer emits a compressive pulse through the concrete while a receiving transducer records its arrival time. The calculated pulse velocity is a direct indicator of concrete uniformity, elastic modulus and the presence of cracking, voids or deterioration along the transmission path. Applied in direct, semi-direct or indirect mode depending on site access constraints.
| Application | Diagnostic Basis |
|---|---|
| Concrete quality assessment | Higher velocity indicates denser, better-consolidated material |
| Crack depth estimation | Indirect transmission path lengthens travel time around crack |
| Uniformity mapping | Velocity grid identifies variable or degraded zones across a member |
| SonReb strength correlation | Combined with rebound hammer for reliable in-situ strength estimate |
Schmidt Hammer
A hardened steel plunger spring-loaded against the concrete surface generates a controlled rebound whose magnitude correlates with surface hardness, compressive strength and carbonation depth with no consumables or coring required. Widely used for in-situ strength estimation, uniformity mapping and identifying zones of deterioration across large surface areas.
| Application | |
|---|---|
| Compressive strength estimation | Rebound number correlated to surface hardness via calibration curves |
| Uniformity mapping | Grid-based survey identifies weak or variable zones across large areas |
| Carbonation depth indication | Reduced rebound in carbonated surface layer flags durability risk |
| Deterioration screening | Rapid non-destructive triage before targeted coring or testing |
Half-Cell Potential
A multi-channel transducer array transmits and receives shear-wave pulses through the concrete section. Travel-time data is reconstructed into a cross-sectional velocity image — revealing honeycombing, internal cracking, delamination planes and voids that GPR alone may not resolve. Particularly effective where access is limited to one face, or where embedded steel creates GPR shadow zones.
| Application | |
|---|---|
| Honeycombing detection | Velocity contrast in poorly consolidated zones |
| Internal crack imaging | Diffraction at crack tips; depth estimation |
| Delamination mapping | Single-sided access; no EM interference |
| Tendon duct grouting | Identifies ungrouted voids within ducts |