Reactivity of olivine-derived amorphous silica and its potential for use as a supplementary cementitious material
File(s)
Published version
OA Location
Author(s)
Djobo, Jean Noel Yankwa
Draper, Sam
Shanks, Barney
Wong, Hong
Cheeseman, Christopher
Type
Journal Article
Abstract
Traditional supplementary cementitious materials (SCM) are declining in availability because of ongoing transitions in the energy and steel sectors. Olivine is a globally abundant mineral that can be processed to produce low-carbon amorphous silica (APS) with the potential for use as an SCM. This study aims to investigate the reactivity of olivine-derived silica during cement hydration, to optimise its use in concrete. Portland cement pastes at a 0.5 water-to-binder (w/b) ratio with up to 20 wt% APS and up to 4 wt% gypsum, for sulfate adjustment, were assessed. Samples were tested for pozzolanic reactivity, hydration kinetics and phase assemblage using the R3 test, isothermal calorimetry, quantitative XRD and TGA. Mortar samples at a 0.63 w/b ratio containing up to 40 wt% APS were produced for assessing workability and compressive strength development. The results show that APS is highly reactive. High specific surface area and a porous structure promote early sulfate depletion, workability loss and delayed hydration. The dilution effect dominates the early age hydration, resulting in low strengths compared to the control sample. However, additional gypsum can mitigate these undesirable effects by improving the degree of hydration and early age strengths. APS promotes pozzolanic reactions and strength gain over time, achieving compressive strengths ∼50 MPa at 90 days for 20 wt% APS, which exceeds the control.
Date Issued
2025-11-15
Date Acceptance
2025-10-11
Citation
Journal of Building Engineering, 2025, 114
ISSN
2352-7102
Publisher
Elsevier
Journal / Book Title
Journal of Building Engineering
Volume
114
Copyright Statement
© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
License URL
Identifier
10.1016/j.jobe.2025.114379
Subjects
Compressive strength
Construction & Building Technology
DISSOLUTION
Engineering
Engineering, Civil
HYDRATION
Hydration mechanism
Low-carbon cement
NANO-SILICA
Olivine
PERFORMANCE
Science & Technology
Silica
Technology
Publication Status
Published
Article Number
114379
Date Publish Online
2025-10-13