Understanding the role of metakaolin towards mitigating the shrinkage behavior of alkali-activated slag

Fu, B., Cheng, Z., Han, J. and Li, N. (2021) Understanding the role of metakaolin towards mitigating the shrinkage behavior of alkali-activated slag. Materials, 14(22), 6962. (doi: 10.3390/ma14226962)

Abstract

This research investigates the mechanism of metakaolin for mitigating the autogenous and drying shrinkages of alkali-activated slag with regard to the activator parameters, including concentration and modulus. The results indicate that the incorporation of metakaolin can decrease the initial viscosity and setting time. Increasing activator concentration can promote the reaction process and shorten the setting time. An increase in the metakaolin content induces a decrease in compressive strength due to reduced formation of reaction products. However, increasing activator dosage and modulus can improve the compressive strength of alkali-activated slag containing 30% metakaolin. The inclusion of metakaolin can mitigate the autogenous and drying shrinkage of alkali-activated slag by coarsening the pore structure. On the other hand, increases in activator concentration and modulus result in an increase in magnitude of the autogenous and drying shrinkage of alkali-activated slag containing metakaolin. The influence of the activator modulus on the shrinkage behavior of alkali-activated slag-metakaolin binary system should be further investigated.

• Item Type: Articles
• Additional Information: The authors thank the financial support of the National Natural Science Foundation of China (51668001 and 51968060), Key research and development program of Ningxia (2020BDE03009), Natural Science Foundation of Ningxia (2020AAC03195 and 2021AAC03187). The participation of Ning Li was supported by the Postdoctoral Science Foundation of China (2020M680113).
• Keywords: Alkali-activated slag, metakaolin, compressive strength, autogenous shrinkage, drying shrinkage, pore structure.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Li, Dr Ning

Creator Roles

Li, N.: Conceptualization, Validation, Writing – review and editing, Supervision

• Authors: Fu, B., Cheng, Z., Han, J., and Li, N.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Materials
• Publisher: MDPI
• ISSN: 1996-1944
• ISSN (Online): 1996-1944
• Published Online: 17 November 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Materials 14(22): 6962
• Publisher Policy: Reproduced under a Creative Commons License