Publication detail

Structural build-up and breakdown of alkali-activated slag pastes with different order of lignosulfonate and activator addition

BÍLEK, V. KALINA, L. NOVOTNÝ, R.

Original Title

Type

journal article in Web of Science

Language

English

Original Abstract

One of the crucial issues of alkali-activated materials is the application of conventional plasticizers. Lignosulfonate plasticizer (LS) works well for sodium hydroxide-activated slag but loses its efficiency in sodium waterglass-activated slag because of competitive adsorption with silicates. Therefore, the effects of the timing of LS and activator addition on the structural build-up and breakdown of AAS pastes with low-silicate moduli activator (0 to 0.50) were investigated, particularly by means of non-traditional strain sweep tests, which are thoroughly discussed. The rheological tests were correlated with the Vicat needle test and isothermal calorimetry. The results showed the high efficiency of LS in NaOH-activated slag paste over time, regardless of the order of addition of the components of the paste. It was accompanied by a considerable retardation effect of LS on the hydration of AAS. The beneficial effect of LS on the rheological parameters and hydration kinetics decreased rapidly with an increase of the silicate modulus of the activator. The delayed addition of the concentrated silicate-containing activators completely counteracted the slightly beneficial effect of LS and even accelerated the initial structural build-up.

Keywords

Alkali -activated slag; Activator; Lignosulfonate; Time of addition; Structural build-up; Structural breakdown; Oscillatory rheology; Strain sweep test; Payne effect

Authors

BÍLEK, V.; KALINA, L.; NOVOTNÝ, R.

Released

10. 7. 2023

Publisher

ELSEVIER SCI LTD

Location

OXFORD

ISBN

0950-0618

Periodical

Construction and building materials

Year of study

386

Number

červenec

State

United Kingdom of Great Britain and Northern Ireland

Pages from

131557

Pages to

131568

Pages count

URL

https://www.sciencedirect.com/science/article/pii/S0950061823012709

BibTex

@article{BUT183984,
  author="Vlastimil {Bílek} and Lukáš {Kalina} and Radoslav {Novotný}",
  title="Structural build-up and breakdown of alkali-activated slag pastes with different order of lignosulfonate and activator addition",
  journal="Construction and building materials",
  year="2023",
  volume="386",
  number="červenec",
  pages="12",
  doi="10.1016/j.conbuildmat.2023.131557",
  issn="0950-0618",
  url="https://www.sciencedirect.com/science/article/pii/S0950061823012709"
}