Laboratory investigation of electrochemical realkalisation of concrete
van den Hondel, A.W.M.
Concrete specimens were cast and subsequently exposed to elevated levels of carbon dioxide and low relative humidity for a period of 70 weeks. After exposure, 32 specimens were treated by electrochemical realkalisation using a 1 molar sodium carbonate solution and a current density of 1 or 4 A/m2 (steel surface) for 3, 7 or 14 days. Experimental variables were chosen to study the dependence of the effectiveness of realkalisation on cement type (Portland and GGBS), water-cement-ratio, reinforcement geometry and the amount of charge passed (time, current density). The results are presented in terms of acid and water soluble sodium contents of the concrete before and after treatment. Concrete samples were sprayed with phenolphthalein in order to establish the occurrence of a zone of high alkalinity around the reinforcement and the degree of realkalisation
Architecture and Building
To reference this document use:
EUROCORR '98, Working Party 11, Reinforcement Corrosion, Utrecht, NL, 28 September-1 October, 1-6