For effective electrical / half cell potential testing, which component must be accessible?

For effective electrical or half-cell potential testing, the exposed rebar must be accessible. This testing method is used to assess the likelihood of corrosion of the reinforcing steel within concrete structures. The test measures the difference in electrical potential between the rebar and a reference electrode placed on the concrete surface.

Exposed rebar provides a direct electrical connection for the test, allowing for accurate readings of the half-cell potentials. If the rebar is not accessible, effective measurements cannot be obtained, rendering the testing process inefficient. The accuracy of assessing the corrosion risk is highly dependent on the condition and accessibility of the rebar itself, making it the critical component in the testing setup.