INFLUENCE OF MATERIAL CHARACTERISTICS ON ELECTROCHEMICAL REALKALISATION OF CARBONATED CONCRETES

Author(s): Ribeiro, P. H. L. C., R. Meira, G. R. and Ferreira, P. R. R.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 252-259
Total Pages: 8
Language: English

Abstract: This work studied 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. Reinforced concrete specimens were cast with high early strength Portland cement and Portland pozzolan cement and w/c ratios of 0.55 and 0.65. Reinforced concrete covers of 1 and 2 centimetres were also adopted. The specimens were previously carbonated in a carbonation chamber until reinforcement depassivation and afterwards were subjected to realkalisation procedures under an average cathodic current density of 2 A/m2 in respect to the exposed concrete surface. Results show the treatment efficiency for recovering concrete alkalinity. More time and total electrical charge passed are demanded in proportion as w/c ratio decreases, concrete cover thickness increases and when concrete has lower alkalinity reserve. The tendency of reinforcement reaching the passive condition is observed by corrosion potential measurements and 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 that.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00