TESTING FOR STRAY CURRENT CORROSION IN EARTH COVERED MAGAZINES WITH EOP

摘要

Electro-Osmotic Pulse technology was installed in a group of underground concrete and steel structures. Stray current potential was evaluated as a part of the planned testing procedure. When electric current is passed through steel reinforced concrete, there is a possibility for any reinforcing steel that is electrically isolated to become a bipolar element. This can occur because the passage of current generates a voltage gradient across the steel, and since the steel offers a "path of least resistance," some current will travel this path. This current, commonly called "stray current," is potentially harmful since one end of the steel element will become anodic, causing corrosion of the steel. Such corrosion, if sufficient, can result in cracking and delamination of the concrete, with possible structural consequences. Initial evaluations inside the structures gave some unexpected data values for stray current potentials indicating that the EOP system could be causing significant stray current corrosion of ground loops for the structure lightning protection system surrounding the structure or possibly of the external steel shell of the structure in contact with ground. Further testing was conducted to locate the ground loops and to further investigate possible stray current as a function of percentage of cathodic current directed to the reinforcing steel. This paper describes the test procedures used and test results.