Hydration of hybrid cements at low temperatures: a study on Portland cement-blast furnace slag—Na2SO4

Joseph, S. and Cizer, Ö. (2022) Hydration of hybrid cements at low temperatures: a study on Portland cement-blast furnace slag—Na2SO4. Materials, 15(5), 1914. (doi: 10.3390/ma15051914)

Abstract

Replacement of Portland cement with high volumes of blast furnace slag is known to negatively affect the early-age properties of concrete, particularly at low temperatures. In this study, the effectiveness of Na2SO4 on the mechanical properties, hydration kinetics and microstructure development of a commercial CEM III/B (~69% slag) is investigated at 10 and 20 °C. Na2SO4 enhances compressive strength at both 10 and 20 °C, and at both early (1 and 7 days) and later ages (28 and 90 days). QXRD shows an increase in the degree of alite hydration at 1 day with Na2SO4 addition, while the degree of clinker and slag hydration is similar for all the systems from 7 to 90 days. An increase in ettringite content is observed at all ages in the systems with Na2SO4. Microstructure and pore structure shows densification of hydrates and reduction in porosity on addition of Na2SO4.

• Item Type: Articles
• Keywords: Hydration, microstructure, activation, sulfate, phase assemblage.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Joseph, Dr Shiju

Creator Roles

Joseph, S.: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Visualization, Writing – original draft

• Authors: Joseph, S., and Cizer, Ö.
• 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: 04 March 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Materials 15(5): 1914
• Publisher Policy: Reproduced under a Creative Commons License