Novel perspective to explain the retarding effect of organic admixtures in silicate-activated slag

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F22%3APU145959" target="_blank" >RIV/00216305:26310/22:PU145959 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Novel perspective to explain the retarding effect of organic admixtures in silicate-activated slag

Original language description

One with the issues of alkali-activated materials is their incompatibility with conventional organic admixtures, which means that they do not improve their properties as expected on the basis of their role in the Portland cement-based system or even have adverse effects. This is also true for hexylene glycol, on which the commercial shrinkage-reducing admixture is based. In previous studies, we observed that it can reduce the drying shrinkage of alkali-activated slag (AAS), but the main reason was its adverse effect on the hydration of AAS since the early ages and related coarse pore structure. In the present study, calorimetric studies showed that a great effect of hexylene glycol and some other alcohols is especially pronounced for a high silicate modulus (around two). This was confirmed by gelation experiments, in which the activating solution was mixed with calcium hydroxide, and organic additives were used. These tests revealed that the acceleration of gelation of silicates occurs for the same admixtures as the retardation of hydration and follows the same trend. A similar effect was observed for the gelation of silicate sol by NaCl solution, showing that the destabilization of silicates by organic additives is at the origin of the affected hydration of silicate-activated slag.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

<a href="/en/project/GA20-26896S" target="_blank" >GA20-26896S: Towards the organic admixtures tailoring for alkali-activated slag-based systems</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

SP-354: Superplasticizers and Other Chemical Admixtures in Concrete - Conference Proceedings

ISBN

978-1-64195-185-2

ISSN

0193-2527

e-ISSN

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Number of pages

11

Pages from-to

49-60

Publisher name

American Concrete Institute

Place of publication

Milán

Event location

Milán

Event date

Jul 10, 2022

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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