ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

  


Title: Mechanism of Chloride Ion Adsorption in Cement Hydrates as per Time-Dependent Behavior

Author(s): In-Seok Yoon and Tatsuhiko Saeki

Publication: Materials Journal

Volume: 118

Issue: 1

Appears on pages(s): 41-53

Keywords: adsorption behavior; AFm phase; Ca/Si ratio; chloride binding; C–S–H phase

DOI: 10.14359/51725988

Date: 1/1/2021

Abstract:
The purpose of this study was to explore the mechanism of the interaction between cement hydrates and chloride ions by examining the time-dependent behavior of chloride ion adsorption. The CH and AFt phases had no role in the adsorption of chloride ions. The AFm phase clearly adsorbed chloride ions rapidly, and the trend was clearly observed over the 20 days of the test period. The ion exchange reaction for adsorption was nearly stopped after 40 days. The C–S–H phase showed an adsorption behavior with three stages, and the trend depended on the Ca/Si ratio. The C–S–H phase showed a complicated adsorption behavior by not only physical adsorption that progressed relatively faster but also by slow chemical adsorption. The highest chloride adsorption capacity was observed for the C–S–H phase with a Ca/Si ratio of 1.50.