Stray Current Induced Corrosion in Reinforced Concrete Parking Garage
A new five-level parking garage is constructed in Arizona and located adjacent to multiple high voltage transmission lines. The contractor first experienced electrical shocks as they started construction of the third level. For obvious safety concerns, construction phasing was altered and an electromagnetic consultant was hired to provide a thorough investigation.
The electromagnetic specialist measured electrostatic and magnetic induced voltage/current and recommended installing a grounding system to resolve the electrical shock issue. The grounding system is designed to establish a low resistance path to ground. When metals are placed in the electromagnetic field, they act like an antenna picking up a voltage related to the magnetic flux, or the rate of change in the magnetic field. If the induced voltage on metal discharges through an electrolyte, such as concrete, the result can be corrosion. To minimize the effects of corrosion… Read more here.
Sara S. Tabatabaei, Ph.D., P.E., is a Structural Restoration Engineer at Walker Consultants in Houston, TX. She can be reached at firstname.lastname@example.org.
Alfredo Bustamante, P.E., CDT, is a Vice President and Managing Director of Forensic Restoration and Building Envelope Services at Walker Consultants. He can be reached at ABustamante@walkerconsultants.com.