Chloride ion binding behavior of deicing chlorides under freeze-thaw environment

Author(s): K. Hashimoto, H. Yokota, Y. Sato, T. Sugiyama
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 622-629
Total Pages: 7
Language: English

Abstract: 
Chlorides of deicing agents accelerate the deterioration due to frost damage under freezethaw environment. It is generally known that phase changes of hydration products, such as formation of Friedel’s salt and ettringite, occur due to penetration of chloride ion into cement hardened matrix. Ettringite formation leads volume expansion and cracks. Monosulfate has much higher binding capacity of chloride ion than ettringite. By contrast, chloride ion penetration causes corrosion of reinforcing bars.

In the previous researches, chloride ion movement and binding capacity in hardened concrete have been reported. However, there are few reports on chloride ion from deicing agents, phase change of hydration products and binding capacity under freeze-thaw environment.

The purpose of this research is to clarify the chloride ion binding under freeze-thaw environment with classifying the chlorides according to total, soluble and fixed chloride.

As the results, Chloride binding was retarded under freeze-thaw environment. In using NaCl of deicing agents, binding chlorides was accelerated than CaCl₂. Chloride binding behavior could be changed by effect of addition of AE agent that is entraining finer air voids agent against frost damage. Relationships between soluble, fixed and total chlorides under freeze-thaw environment, which are important issue on combined deterioration of chloride attack and frost damage, were obtained.

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