Electrochemical realkalisation of carbonated concretes - Influence of material characteristics and thickness of concrete reinforcement cover

摘要

This work studies the influence of concrete characteristics, such as cement type and water to cement ratio, and concrete cover thickness on the electrochemical realkalisation of carbonated concretes. Results show the treatment efficiency for recovering concrete alkalinity. More time and total electrical charge passed are demanded in proportion as water to cement ratio decrease, concrete cover thickness increase and when concrete has lower alkalinity reserve. The tendency of reinforcement reaching passive condition is observed by corrosion potential measurements. For this variable, concretes that demand more charge and time for realkalisation reach the passive condition in a shorter time. Corrosion current density shows a decrease tendency over time and, although not reaching the level that represents passive condition in most of the cases, it was not far from this reference.