| 英文摘要 |
This study investigated the efficiency of an electrochemical realkalisation technique to repair fire-damaged reinforced concrete. The two experimental specimens used were a normal-strength specimen and a high-strength specimen of fire-damaged reinforced concrete. In the experiment, an electric current was passed through the two specimens via the DC transformer, for different power-on times (1-7 days), current densities (0.5 A / m2, 1.0 A / m2 and 1.5 A / m2), and different electrolytes (Na2CO3, Na2SiO3 and MgCl2). Then electrolyte potential and current resistance for the anolyte were measured. The results showed current density of anolyte at approximately 1.0 A/㎡for both normal strength specimen and 1.5 A/㎡for high strength specimen show significant repair after 7 days of electrochemical realkalisation. The electrolyte potential of anolyte showed gradual reduction, and the resistance increased in the area near the surface of the concrete. Current density for the normal strength specimen was maintained at approximately 1.0 A/㎡, while the high strength specimen was held at 1.5 A/㎡. Comparing Na2CO3 and MgCl2 of the specimens after realkalisation, the former has a lower current potential and higher current resistance in the anolyte, at the same current density and powered time. Under previous conditions, two electrolytes can restore an alkaline environment to fire-damaged reinforced concrete after electrochemical realkalisation. |
