Corrosion of Steel Fiber Subjected to Stray Current Interference

摘要

Steel fiber-reinforced concrete (SFRC) can be an ideal substitute for conventional steel reinforcement in railway tunnel lining construction due to its high strength and good fire resistance. On the other hand, it is still not clear whether discontinuous steel fibers can pick up and transfer stray current and lead to similar corrosive attack as that occurs in conventional steel reinforcement. These were evaluated through voltammetry tests and electrochemical impedance spectroscopy (EIS) before and after simulated railway stray direct current (DC) and alternating current (AC) interferences. In addition to instrumental methods in electrochemistry, numerical modeling based on the boundary element method (BEM) modeling indicates that discrete steel fibers can pick up and transfer stray currents. This was validated by the electrochemical investigations conducted using both aqueous and solid (mortar) electrolytes. It can be concluded that steel fibers have high corrosion resistance to stray A C and DC interferences even with the presence of a small amount of NaCl in the electrolyte.