Abstract:
The passive film in internal reinforcement corrosion was destroyed by the fire-damaged of rein-forced concrete. However, the destruction of the passive film is caused by the disappearance of the alkaline environment around reinforced corrosion. This study was to establish the modeling pH value for electrochemical realkalisation to repair of fired-damaged reinforced concrete. The pH value of fire-damaged reinforced concrete is determined by the equation
, in which j is the circuit current density (A/ m2), T is power-on time (s), d is neutral depth (mm), fcu is actual strength of concrete after fire-damaged (MPa), k is the parameter of porosity. The parameter of k of porosity for the or-dinary strength fire-damaged is 6.3 × 10−4, while the high-intensity fire-damaged is 2.5 × 10−5. This equation can be used to estimate the pH value for fire-damaged reinforced concrete to repair by electrochemical realkalisation.