Conduct a half-cell potential corrosion survey on a parking structure deck per ASTM C876

Steps

1. Confirm the test method's scope: ASTM C876 estimates the electrical half-cell potential of uncoated reinforcing steel in concrete to assess the probability of active corrosion — it does not measure corrosion rate.
2. Establish an electrical connection to the reinforcing steel and prepare a survey grid across the deck/slab area to be tested, following the standard's guidance on grid spacing and reference electrode placement.
3. Use a copper/copper sulfate (CSE) or silver/silver chloride reference electrode with a portable voltmeter to record potential differences at each grid point, wetting the concrete surface as required by the method to ensure electrical continuity.
4. Map recorded potentials to identify zones of high corrosion probability versus low probability per the standard's guidance, and correlate high-probability zones with visual distress (staining, cracking, delamination) found during the sounding survey.
5. Combine half-cell results with chloride content sampling and concrete cover measurements, since half-cell potential alone indicates likelihood of corrosion activity, not its severity or rate.