Effect of cathodic protection on steel-concrete bond strength using ion migration measurements

Impressed current cathodic protection (ICCP) is a widely used method to protect steel reinforcements against corrosion. Bond degradation between concrete and steel at protection and overprotection levels was studied. Two types of materials were tested: an ordinary Portland cement (OPC) and a mixture of 85%25 OPC and 15%25 fly ash (OPC/FA). Concrete specimens were immersed in a 3.5%25 sodium chloride (NaCl) solution. Chemical analysis of sodium, potassium and hydrogen ions was performed using atomic absorption spectrophotometry (AAS). Hydrogen ion content was monitored using electrochemical impedance spectroscopy (EIS). Mechanical behaviour was analysed by means of pullout tests, and microstructure characterisation was carried out using scanning electron microscopy (SEM). Sodium, potassium and hydrogen ions were found at the concrete-steel interface. The mechanical properties of the specimens were poorer at overprotection level than at protection level. © 2011 Elsevier Ltd. All rights reserved.

Bond strength; Cathodic protection; Concrete-steel interface; Hydrogen ions; Overprotection; Potassium; Sodium Atomic absorption spectrophotometry; Bond degradation; Concrete specimens; Hydrogen ions; Impressed-current cathodic protections; Ion migration; Mechanical behaviour; Microstructure characterisation; Ordinary Portland cement; Overprotection; Protection level; Pull-out test; Sodium chloride solution; Steel reinforcements; Steel-concrete; Bond strength (materials); Cathodic protection; Chemical analysis; Concrete beams and girders; Electrochemical impedance spectroscopy; Fly ash; Hydrogen; Mechanical properties; Portland cement; Potassium; Scanning electron microscopy; Sodium; Sodium chloride; Ions

VIVO