eprintid: 1560407 rev_number: 30 eprint_status: archive userid: 608 dir: disk0/01/56/04/07 datestamp: 2017-06-30 14:35:16 lastmod: 2021-09-20 00:29:07 status_changed: 2017-06-30 14:55:56 type: article metadata_visibility: show creators_name: Wang, Y creators_name: Nanukuttan, S creators_name: Bai, Y creators_name: Basheer, PAM title: Influence of combined carbonation and chloride ingress regimes on rate of ingress and redistribution of chlorides in concretes ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F44 keywords: Air permeability; Carbonation; Chloride profile; Chloride migration; pH profile; Combined exposures note: Copyright © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). abstract: In majority of exposure environments for concrete structures, there is a high probability of the cyclic occurence of both chloride ingress and carbonation. This paper reports a detailed investigation on the influence of carbonation on both the ingress and distribution of chlorides in three different types of concretes, by comparing results from exposure to chlorides, chlorides before carbonation and chlorides after carbonation. Concretes studied were of 0.55 water-binder ratio with 100% Portland Cement (PC), 70% PC + 30% pulverized fuel ash (PFA) and 85% PC + 10% PFA + 5% microsilica (MS) as binders. Chloride profiles were compared to assess the effects of all variables studied in this research. The effect of carbonation was quantified by measuring the consumption of hydroxyl ions (OH−), air permeability and chloride migration coefficient. The results indicated that carbonation of concrete increases chloride transport, but the precise nature of this is dependent on the combined regime as well as the type of binder. In general, it was found that carbonation of chloride contaminated concretes results in a decrease of their chloride binding capacity, that is it releases the bound Cl− in concretes and pushes chlorides inwards, as has been established previously by other researchers. However, it is established in this research that the combined regimes detrimentally affect the service life of concrete structures, particularly when chloride induced corrosion is a concern. date: 2017-06-01 date_type: published publisher: ELSEVIER SCI LTD official_url: http://doi.org/10.1016/j.conbuildmat.2017.02.121 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1295311 doi: 10.1016/j.conbuildmat.2017.02.121 lyricists_name: Bai, Yun lyricists_id: YBAIX06 actors_name: Waragoda Vitharana, Nimal actors_id: NWARR44 actors_role: owner full_text_status: public publication: Construction and Building Materials volume: 140 pagerange: 173-183 pages: 11 issn: 1879-0526 citation: Wang, Y; Nanukuttan, S; Bai, Y; Basheer, PAM; (2017) Influence of combined carbonation and chloride ingress regimes on rate of ingress and redistribution of chlorides in concretes. Construction and Building Materials , 140 pp. 173-183. 10.1016/j.conbuildmat.2017.02.121 <https://doi.org/10.1016/j.conbuildmat.2017.02.121>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1560407/1/Bai_1-s2.0-S0950061817303136-main.pdf