GROUND PENETRATING RADAR
Often referred to as “concrete x-ray” or “concrete scanning”, GPR is ideal for the locating and positioning of reinforcing or structural elements, locating of metallic or non-metallic services and the detection of voids.
We have multiple GPR collection units and the largest range of antennae frequencies in South Australia. This enables us to provide our clientele with the best available service and the sharpest and most accurate profiles.
GROUND PENETRATING RADAR
2.6Ghz very high resolution for concrete – Maximum range 600mm. (under ideal conditions)
1.5Ghz high resolution for concrete – Maximum range 500mm. (under ideal conditions)
900Mhz medium resolution for concrete and soil – Maximum range 900mm.
400Mhz medium resolution for soil – Maximum range 4 metres. (Soil condition dependant)
270Mhz medium resolution for soil – Maximum range 7 metres (Soil condition dependant)
Penetration of the radar signal for soil surveys is dependant upon local soil conditions
Much like GPR, ultrasound is also a “Pulse – Echo” technology where a high frequency sound pulse is injected into the structure and the resultant echo is then analysed. Sound waves comprise of 2 sections which are used independently to perform differing tasks. The MIRA and PUNDIT arrays are multi point tomographical ultrasounds utilising “Shear (S)” wave technology. Shear waves react to air and water, yet are able to pass through steel making it ideal for void and horizontal delamination detection. Structures with dense reinforcing, particularly at the surface, can obscure other forms of void detection such as GPR. Dependant upon size and how prolific the void structures are, the MIRA and PUNDIT arrays have a visual potential of up to 1.5 metres in depth.
Sonic Echo, Impulse Response and Ultrasonic Pulse Velocity utilize “Compression (P)” wave technology. SE/IR is used mainly to measure distance in long tubular structures such as concrete piles, however SE/IR and UPV can also be utilised to detect voiding and delaminations. Our OLSENS NDE 360 equipment has the capability to measure up to 30 metres deep, dependant upon local site conditions.
Our latest addition is the ASC SURFER handheld 2 point dry contact ultrasound for crack depth analysis to 50mm and basic compressive strength estimation
CORROSION POTENTIAL TESTING
The potential for corrosion is measured using “Half Cell” testing methods. Put simply, a small current is passed through the reinforcing and the resultant increase in negative ions, conducive to corroding reinforcing, can be measured.
GPR data can be collected in 2D or 3D formats can be transferred into a CAD format to be incorporated with existing drawings.
Not all surveys require processing and can often be marked directly on site, however dependant upon the Client’s requirements, we can issue reports in various forms such as CAD, spead sheet or 2D & 3D images.