Publication detail

Correlating Hydration of Alkali-Activated Slag Modified by Organic Additives to the Evolution of Its Properties

BÍLEK, V. KALINA, L. DVOŘÁK, R. NOVOTNÝ, R. ŠVEC, J. MÁSILKO, J. ŠOUKAL, F.

Original Title

Type

journal article in Web of Science

Language

English

Original Abstract

This study investigates the relationships between the hydration kinetics of waterglass-activated slag and the development of its physical-mechanical properties, as well as its color change. To modify the calorimetric response of alkali-activated slag, hexylene glycol was selected from various alcohols for in-depth experiments. In presence of hexylene glycol, the formation of initial reaction products was restricted to the slag surface, which drastically slowed down the further consumption of dissolved species and slag dissolution and consequently delayed the bulk hydration of the waterglass-activated slag by several days. This allowed to show that the corresponding calorimetric peak is directly related to the rapid evolution of the microstructure and physical-mechanical parameters and to the onset of a blue/green color change recorded as a time-lapse video. Workability loss was correlated with the first half of the second calorimetric peak, while the most rapid increase in strengths and autogenous shrinkage was related to the third calorimetric peak. Ultrasonic pulse velocity increased considerably during both the second and third calorimetric peak. Despite the modified morphology of the initial reaction products, the prolonged induction period, and the slightly reduced degree of hydration induced by hexylene glycol, the overall mechanism of alkaline activation remained unchanged in the long-term perspective. It was hypothesized that the main issue of the use of organic admixtures in alkali-activated systems is the destabilizing effect of these admixtures on soluble silicates introduced into the system with an activator.

Keywords

alkali-activated slag; calorimetry; microstructure; retardation; pore solution; organic admixture; color change; shrinkage; setting

Authors

BÍLEK, V.; KALINA, L.; DVOŘÁK, R.; NOVOTNÝ, R.; ŠVEC, J.; MÁSILKO, J.; ŠOUKAL, F.

Released

25. 2. 2023

Publisher

MDPI

Location

Basel, Switzerland

ISBN

1996-1944

Periodical

Materials

Year of study

Number

State

Swiss Confederation

Pages from

Pages to

Pages count

URL

https://www.mdpi.com/1996-1944/16/5/1908

Full text in the Digital Library

http://hdl.handle.net/11012/209176

BibTex

@article{BUT183050,
  author="Vlastimil {Bílek} and Lukáš {Kalina} and Richard {Dvořák} and Radoslav {Novotný} and Jiří {Švec} and Jiří {Másilko} and František {Šoukal}",
  title="Correlating Hydration of Alkali-Activated Slag Modified by Organic Additives to the Evolution of Its Properties",
  journal="Materials",
  year="2023",
  volume="16",
  number="5",
  pages="18",
  doi="10.3390/ma16051908",
  issn="1996-1944",
  url="https://www.mdpi.com/1996-1944/16/5/1908"
}