University of Oulu

Tero Luukkonen, Harisankar Sreenivasan, Zahra Abdollahnejad, Juho Yliniemi, Anu Kantola, Ville-Veikko Telkki, Paivo Kinnunen, Mirja Illikainen, Influence of sodium silicate powder silica modulus for mechanical and chemical properties of dry-mix alkali-activated slag mortar, Construction and Building Materials, Volume 233, 2020, 117354, ISSN 0950-0618, https://doi.org/10.1016/j.conbuildmat.2019.117354.

Influence of sodium silicate powder silica modulus for mechanical and chemical properties of dry-mix alkali-activated slag mortar

Saved in:
Author: Luukkonen, Tero1; Sreenivasan, Harisankar1; Abdollahnejad, Zahra1;
Organizations: 1Fibre and Particle Engineering Research Unit, University of Oulu, P.O. Box 4300, FI-90014, Finland
2NMR Research Unit, Faculty of Science, University of Oulu, P.O. Box 4300, FI-90014, Finland
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe2019110136231
Language: English
Published: Elsevier, 2020
Publish Date: 2021-10-31
Description:

Abstract

Sodium silicate powders with different SiO₂/Na₂O (silica modulus) were characterized by solubility rate, pH, and chemical structure (by ²⁹Si MAS-NMR) and compared in the preparation of one-part (or dry-mix) alkali-activated blast furnace slag mortar. The low SiO₂/Na₂O indicated the beneficial presence of less-polymerized silica (Q¹ and Q² Si environments) and thus faster dissolution. Consequently, using sodium silicates with SiO₂/Na₂O of 0.9, 2.1, and 3.4 resulted 28 d compressive strengths of 103, 80, and 2 MPa, respectively, with increasing setting time and decreasing heat release in isothermal calorimetry. Adjustment of activator SiO₂/Na₂O from 2.1 or 3.4 to 0.9 by adding NaOH powder resulted increased or decreased mechanical properties of mortar, respectively, depending on the initial silica modulus. These properties were not, however, similar to those obtained with sodium silicate having SiO₂/Na₂O of 0.9 originally. Depending on the case, the added NaOH can be consumed for dissolving sodium silicate activator, slag, or the forming (C,N)-(A)-S-H gel.

see all

Series: Construction & building materials
ISSN: 0950-0618
ISSN-E: 1879-0526
ISSN-L: 0950-0618
Volume: 233
Article number: 117354
DOI: 10.1016/j.conbuildmat.2019.117354
OADOI: https://oadoi.org/10.1016/j.conbuildmat.2019.117354
Type of Publication: A1 Journal article – refereed
Field of Science: 116 Chemical sciences
215 Chemical engineering
216 Materials engineering
Subjects:
Funding: This work was supported by the Finnish Funding Agency for Technology and Innovation (Tekes) (project GEOBIZ, grant number 1105/31/2016). Anu Kantola and Ville-Veikko Telkki acknowledge the financial support received from the Kvantum Institute (University of Oulu) and the Academy of Finland (grants #289649 and 294027).
Academy of Finland Grant Number: 289649
294027
Detailed Information: 289649 (Academy of Finland Funding decision)
294027 (Academy of Finland Funding decision)
Dataset Reference: Supplementary data:
  https://ars.els-cdn.com/content/image/1-s2.0-S0950061819328065-mmc1.pdf
Copyright information: © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http:/creativecommons.org/licenses/by-nc-nd/4.0/