Mahroo Falah, Katja Ohenoja, Robert Obenaus-Emler, Paivo Kinnunen, Mirja Illikainen, Improvement of mechanical strength of alkali-activated materials using micro low-alumina mine tailings, Construction and Building Materials, Volume 248, 2020, 118659, ISSN 0950-0618, https://doi.org/10.1016/j.conbuildmat.2020.118659
Improvement of mechanical strength of alkali-activated materials using micro low-alumina mine tailings
|Author:||Falah, Mahroo1; Ohenoja, Katja1; Obenaus-Emler, Robert2;|
1Fiber and Particle Engineering Research Unit, Faculty of Technology, University of Oulu, 90014 Oulu, Finland
2Montanuniversität Leoben, Peter-Tunner Straße 5, 8700 Leoben, Austria
|Online Access:||PDF Full Text (PDF, 3.7 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020110288973
|Publish Date:|| 2020-11-02
Low-alumina mine tailings (MTs) have shown the possibility of being a precursor in the production of alkali-activated materials (AAMs). The effects of the addition of sub-micron MTs (10 wt%) with the average size of 400 nm to improve the performance of AAMTs with alkali activator (10, 15, 20, and 30 wt% sodium silicate) were investigated by using X-ray diffractometry (XRD), Attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and nitrogen adsorption technique (BET). The mechanical properties of the materials were also analyzed. The results indicate that the addition of sub-micron MTs to AAMTs plays an important role in mineral compositions and enhances the mechanical strength performance in comparison to plain AAMTs, especially after just 7 days of aging. This result is attributed to the different microstructure between AAMTs and sub-micron MTs. BET results showed that the addition of sub-micron MTs reduces the total porosity of alkali-activated products and changes the pore structure. The pores of AAMTs were refined by the filling effects of sub-micron particles and the enhancement of the hydration process due to the nucleation effect of those sub-micron particles. This could be a significant reason for the increase in early age mechanical strength. This work introduces a novel approach to improve the performance of tailings-based alkali-activated materials using nano-sized precursors.
Construction & building materials
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
216 Materials engineering
The provided results in this paper are part of the research project “Integrated mineral technologies for more sustainable raw material supply” (ITERAMS). The funding received from the European Union’s Horizon 2020, research, and innovation program under grant agreement No. 730480.
|EU Grant Number:||
(730480) ITERAMS - Integrated mineral technologies for more sustainable raw material supply
© 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).