CHLORIDE DIFFUSION CHARACTERISTICS OF CONCRETE UNDER COMBINED CONDITIONS OF CHLORIDES AND CARBONATION

Author(s): Myung K. Lee, Sang H. Jung, Byung H. Oh, Sung W. Yoo, Seung Y. Jang and Ji S. Kim
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 431-442
Total Pages: 961
Language : English

Abstract: Recently, the corrosion of reinforced concrete structures has received great attention
because major important infrastructures are often constructed under severe environments.
Nevertheless, most studies were confined to the deterioration of concrete structures under
single deteriorating action of chloride ingress only.
The purpose of the present study is therefore to explore the influence of carbonation on
chloride penetration in concrete structures and also to examine the chloride diffusivity of
concrete under combined action of chloride and carbonation. Several series of concrete
specimens have been tested. The test results indicate that the chloride penetration is more
pronounced when the carbonation process is combined with the chloride ingress. It is also
shown that the ratio of water-soluble (free) chloride to the acid-soluble (total) chloride content
is higher for the case of carbonated test series than the case of normal non-carbonated test
series. This may cause more vulnerable situation to the corrosion of steel bar when chloride
ingress is combined with carbonation. It is shown that the chloride contents of fly ash-added
mixtures according to the depth are much larger under the condition of cyclic immersion in
chloride and accelerated carbonation than under cyclic immersion in chloride and natural air
condition. This may be due to the fact that the pozzolan reaction of fly ash in cement mixtures
may accelerate the carbonation and thus this may lead to more ingress of chloride ions in
concrete. The present study allows more realistic assessment of durability for concrete
structures which are subjected to combined environment of chlorides and carbonation.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00