Concrete Scanning – 118, Church Street, Parramatta

W3 Networks commissioned Perfect Concrete Care to carry out non-destructive investigations at 118 Church Street, Lvl 28, Parramatta. The objective of the investigation was to examine existing reinforcing information and to check the wall for active power.

The Challenges

Fieldwork Carried Out:

The investigation utilised ground penetrating radar equipment in order to establish reinforcement content in the wall.

Profile information was collected in both longitudinal and transverse directions at various locations for establishing the reinforcing/post-tensioning cables in the structure.

Techniques Adopted:

Concrete Scanning is a relatively new technique. They use it in the construction industry, known as GPR(Ground Penetrating Radar). It is a non-destructive investigation technique that uses UHF electromagnetic pulses to provide a high-resolution reflection image of the subsurface.

Reflections of these electromagnetic pulses occur at the boundaries of materials with different dielectric constants. Detecting changes in materials, and highlighting steel embedded within the concrete are its other usages for example. The reflections are then used to build up a radar-gram profile of the structure at each scan location.

The recorded data is then analysed in terms of shape, phase, travel time, and signal amplitude to build up a picture of buried objects within the structure.

Hilti PS1000 helped collect the data. It also allowed penetration depths up to approximately 500mm.

The Result:

The Concrete Scanning investigation revealed that the existing walls in the location shown above are conventionally reinforced (steel bars / reo only), all reinforcement was identified and the client was informed and present while scanning was undertaken.