FPrimeC Solutions was retained by The Condominium Building Manager (Client) to perform Parking Garage Inspection in a condominium building in Toronto, Ontario. The client was interested to evaluate the present condition of concrete slab, and evaluate the likelihood of active corrosion. The driveway and garden area over the parking garage increase the risk of chloride ion penetration, which can result in higher probability of steel corrosion. The main objective of the project was to measure the likelihood of corrosion of steel bars in the concrete slabs by means of non-destructive testing.
Solution: Half-Cell Corrosion Potential Mapping
Following communication with the client, and initial site visit, a comprehensive test plan was designed and proposed to the client. The proposed methodology involved three major steps:
- Visual Inspection and Hammer Sounding
- Ground Penetrating Radar – GPR (Learn more)
- Half-Cell Corrosion Potential Mapping (Learn More)
A walk-through Visual Inspection and Hammer Sounding were initially proposed over select areas on the parking roof slab. The goal was to find areas which are prone to corrosion of steel rebar for further investigation with Half-Cell corrosion potential mapping.
GPR scanning was used to determine the location of embedded rebar in concrete prior to removing the concrete cover at the reference points. GPR enabled FPrimeC engineers to pin-point the exact location of steel rebars, and minimize the damage to concrete during concrete removal process. Moreover, GPR scans were used to assess the rebar depth, and overall condition of the slab.
Half-Cell corrosion mapping was used to determine the probability (likelihood) of active corrosion in the steel rebar. The Half-Cell test was conducted according to the recommendations of the ASTM C876 on a systematic test grid and the measurements were used to create comprehensive contour map of corrosion activity for select test areas.