MEASUREMENT OF POLARIZED POTENTIALS IN CONCRETE BRIDGE DECKS.

An investigation was conducted to determine the best method of measuring the polarized potential of the reinforcing steel in a cathodically protected bridge deck. The use of carbon rods and copper-copper sulfate and zinc-zinc sulfate half-cells as probes was studied in laboratory slabs and bridge decks. The carbon probes were found to be more accurate and reliable; the half-cells produced variable results. The coke layer was found to act as a half-cell and its voltage had to be taken into account when measuring the polarized potentials in the deck.