Impact of water content on the performance of alkali-activated slag concretes

Presenter Information

Susan A. Bernal, Department of Materials Science and Engineering, The University of Sheffield, UKFollow
John L. Provis, Department of Materials Science and Engineering, The University of Sheffield, UK
Jannie S.J. van Deventer, Department of Chemical & Biomolecular Engineering, The University of Melbourne; Zeobond Pty Ltd, Australia

Location

University of Leeds

Keywords

Alkali-activated slag concretes, water content, mechanical strength, transport properties, durability

Abstract

In this study, we report the effect of varying the water/binder (w/b) ratio on the performance of sodium silicate activated concretes. Compressive strength development and water transport properties of these concretes were assessed, along with their resistance to carbonation. The results demonstrate that varying the water content within a reasonable range induced negligible changes in the compressive strengths of these concretes, when a constant paste content was used. A direct correlation between the w/b ratio and the amount of permeable voids in the concretes was not identified. The carbonation behaviour of these concretes changes prominently depending on the CO2 concentration of exposure, meaning that comparable accelerated carbonation rates were observed at varying w/b ratios, conversely to observations under natural carbonation conditions where w/b was significant in defining the carbonation rate.