Chloride binding in Portland composite cements containing metakaolin and silica fume
Journal article, 2022

This paper investigates how the composition of Portland composite cements affects their chloride-binding properties. Hydrated cement pastes prepared with a reference Portland cement and composite Portland cements containing metakaolin and/or silica fume were exposed to NaCl or CaCl2 solutions. Chloride-binding isotherms were determined and the hydrate assemblage was investigated using TGA, XRD, 27Al NMR, 29Si NMR and thermodynamic modelling. Compared to the reference Portland cement paste, silica fume replacement did not alter the chloride-binding capacity. The metakaolin replacement resulted in the highest chloride-binding capacity. When combining silica fume with metakaolin, the chloride binding is similar to the reference Portland cement. In this study the differences in chloride binding were linked not only to changes in the AFm content, but also to alterations in the Al-uptake and chain length of the C(-A)-S-H.

Friedel's salt

Chemical and physical chloride binding

Durability

Supplementary cementitious materials (SCM)

Sustainability

Author

Arezou Baba Ahmadi

Chalmers, Architecture and Civil Engineering, Building Technology

Alisa Machner

Technical University of Munich

Wolfgang Kunther

Technical University of Denmark (DTU)

João Figueira

Umeå University

Petter Hemstad

Norwegian University of Science and Technology (NTNU)

Klaartje De Weerdt

Norwegian University of Science and Technology (NTNU)

Cement and Concrete Research

0008-8846 (ISSN)

Vol. 161 106924

Subject Categories

Ceramics

Bio Materials

Biomaterials Science

DOI

10.1016/j.cemconres.2022.106924

More information

Latest update

8/19/2022