Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Evolution of pore solution chemistry, electro-osmosis and rebar corrosion rate induced by realkalisation
Abstract The electrochemical repair methods known as realkalisation or chloride removal, although increasingly applied, still require fundamental understanding. In the case of realkalisation, the development of an electro-osmosis is claimed, which would introduce the carbonate ions into the concrete matrix; however this electroosmosis has still not been demonstrated. In the present paper, a laboratory trial is reported showing the different processes occurring throughout the experiment. In carbonated concrete, a noticeable increase in the volume of the catholyte could be identified, with the subsequent incrase in the amount of carbonate, and volume decrease in the anolyte, which has been taken as an indicative of electro-osmosis. Variations of pH and the concentration of different ions have been monitored enabling the deduction that $ OH^{−} $, $ Na^{+} $ are driven by the electrical field while $ K^{+} $ and CO3− are moved by other types of driven forces. Calculation of the potential zeta of carbonated concrete, as well as the theoretical electrical charge needed for realkalisation, is given. Finally, the corrosion rate values measured two months further after finishing the tests showed that the steel does not seem to be repassivated, although this result has to be interpreted with precaution due to the amount of oxides reduced on the steel during the treatment.
Evolution of pore solution chemistry, electro-osmosis and rebar corrosion rate induced by realkalisation
Abstract The electrochemical repair methods known as realkalisation or chloride removal, although increasingly applied, still require fundamental understanding. In the case of realkalisation, the development of an electro-osmosis is claimed, which would introduce the carbonate ions into the concrete matrix; however this electroosmosis has still not been demonstrated. In the present paper, a laboratory trial is reported showing the different processes occurring throughout the experiment. In carbonated concrete, a noticeable increase in the volume of the catholyte could be identified, with the subsequent incrase in the amount of carbonate, and volume decrease in the anolyte, which has been taken as an indicative of electro-osmosis. Variations of pH and the concentration of different ions have been monitored enabling the deduction that $ OH^{−} $, $ Na^{+} $ are driven by the electrical field while $ K^{+} $ and CO3− are moved by other types of driven forces. Calculation of the potential zeta of carbonated concrete, as well as the theoretical electrical charge needed for realkalisation, is given. Finally, the corrosion rate values measured two months further after finishing the tests showed that the steel does not seem to be repassivated, although this result has to be interpreted with precaution due to the amount of oxides reduced on the steel during the treatment.
Evolution of pore solution chemistry, electro-osmosis and rebar corrosion rate induced by realkalisation
Andrade, C. (Autor:in) / Castellote, M. (Autor:in) / Sarría, J. (Autor:in) / Alonso, C. (Autor:in)
1999
Aufsatz (Zeitschrift)
Englisch
| British Library Online Contents | 1999
| Trans Tech Publications | 2010