Effect of carbonation on chloride penetration in concrete

Title: Effect of carbonation on chloride penetration in concrete
Author(s): T. Saeki
Paper category : conference
Book title: Third International RILEM Workshop on Testing and Modelling Chloride Ingress into Concrete
Editor(s): C. Andrade and J. Kropp
Print-ISBN: 2-912143-48-9
e-ISBN: 2912143578
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 381 - 394
Total Pages: 14
Nb references: 13
Language: English

Abstract: When chloride ions ingress and carbonation take place simultaneously in concrete, chloride ions that have been fixed in cement hydrates will be unfixed and become soluble due to the deterioration of cement hydrates caused by carbonation. It has been observed that chloride ions concentrate in the region where carbonation has not occurred. Therefore, for concrete subjected to both chloride ions ingress and carbonation the corrosion of steel bars in it may take place at an early stage and the rate of corrosion may also increase. Therefore, when chloride ions ingress and carbonation are co-existed the prediction of the distribution of chloride ions in concrete is essential to the evaluation of concrete durability. This study is aimed to estimate the effect of carbonation on chloride penetration in concrete through an investigation into the immobilization of chloride ions in cement hydrates and the release of them when alteration of cement hydrates occurs due to carbonation. The available potential for hydrates to immobilize chloride ions and the carbonation-induced release of chloride ions is determined using artificially synthesized cement hydrates, which are immersed in an artificial pore solution. Based on these above experiments, a model characterizing the process of immobilization and release of chloride ions is established and its validity is verified by comparing calculated data with data from tests on cement paste and mortar specimens. The effect of change in micro-structure due to carbonation on chloride penetration was also evaluated in this study.

Online publication: 2002-12-15
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143578.025