Redistribution of chloride in blended cement concrete during storage in various climates

Title: Redistribution of chloride in blended cement concrete during storage in various climates
Author(s): R. Polder
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: 347 - 359
Total Pages: 13
Nb references: 12
Language: English

Abstract: Concrete specimens with various binders including Portland cement, fly ash, blast furnace slag and composite cement and three water-to-cement ratios were subjected to cyclic wetting with salt solution and drying. After salt loading for half a year, chloride profiles were determined. Subsequently, chloride loading was discontinued and specimens were exposed for two years in various climates (20°C 80%RH, outside, fog room). The chloride distribution was measured at the end of the exposure period. Concrete resistivities were measured using embedded electrodes. Considerable redistribution of chloride was found during storage without external chloride load. The results show a large influence of the cement type and the exposure to moisture on redistribution of chloride and on resistivity. Concrete resistivities showed an increase with time in all mixes, with significant differences between Portland and blended cements and with the exposure to moisture. Combining the two types of results, diffusion coefficients and resistivities were correlated. It appears that the resistivity of a particular concrete, both in dependence of exposure to moisture and of composition, reflects its properties with regard to chloride redistribution during a period without external chloride load. The product of resistivity and diffusion coefficient was reasonably constant over the investigated mixes.

Online publication: 2002-12-15
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143578.023