An efficient approach for sustainable fly ash geopolymer by coupled activation of wet-milling mechanical force and calcium hydroxide

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27690%2F22%3A10250519" target="_blank" >RIV/61989100:27690/22:10250519 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0959652622033480" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0959652622033480</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jclepro.2022.133771" target="_blank" >10.1016/j.jclepro.2022.133771</a>

Jazyk výsledku

angličtina

Název v původním jazyce

An efficient approach for sustainable fly ash geopolymer by coupled activation of wet-milling mechanical force and calcium hydroxide

Popis výsledku v původním jazyce

Geopolymer is a potential substitute for high-emission cement production. Therefore, the use of fly ash with high emission as a geopolymer is an environmentally friendly and inexpensive direction. However, fly ash (FA) is a high amorphous precursor with low pozzolanic reactivity making it difficult to be activated by calcium hydroxide. In this study, the coupling of wet-milling mechanical force and calcium hydroxide was used to prepare high-performance alkaline calcium activated geopolymers. Two kinds of FA slurries with different particle sizes of D50 = 2.96 μm and 14.2 μm were prepared, activated by calcium hydroxide (CH) with the content of 4%, 11% and 19%. Results indicated that the increase of calcium hydroxide content was beneficial to developing strength, effectively improving the chloride resistance, compacting the microstructure, but increasing the autogenous shrinkage of the geopolymers. These improvements are especially apparent in the wet-milled fly ash geopolymers (WFA) due to the pre-depolymerization implemented by wet-milled mechanical forces, and coupled with the activation effect of CH to improve the depolymerization efficiency and condensation reaction. The compressive strength of WF-CH-19 was three times higher than that of FA-CH-19, reaching 29.3 MPa at 28 d, and the compressive strength growth of WF-CH-11 even reached 591.67% at 1 d. Meanwhile, the main chain length (MCL) and Al/Si of calcium silicate hydrates were clearly improved, and pore structure was significantly refined with capillary pore increased from 29.79% to 89.23%. In addition, FA and WFA geopolymers have significant advantages over Portland cement in the environmental impact indicators such as E-energy and E-CO2. (C) 2022 Elsevier Ltd

Název v anglickém jazyce

An efficient approach for sustainable fly ash geopolymer by coupled activation of wet-milling mechanical force and calcium hydroxide

Popis výsledku anglicky

Geopolymer is a potential substitute for high-emission cement production. Therefore, the use of fly ash with high emission as a geopolymer is an environmentally friendly and inexpensive direction. However, fly ash (FA) is a high amorphous precursor with low pozzolanic reactivity making it difficult to be activated by calcium hydroxide. In this study, the coupling of wet-milling mechanical force and calcium hydroxide was used to prepare high-performance alkaline calcium activated geopolymers. Two kinds of FA slurries with different particle sizes of D50 = 2.96 μm and 14.2 μm were prepared, activated by calcium hydroxide (CH) with the content of 4%, 11% and 19%. Results indicated that the increase of calcium hydroxide content was beneficial to developing strength, effectively improving the chloride resistance, compacting the microstructure, but increasing the autogenous shrinkage of the geopolymers. These improvements are especially apparent in the wet-milled fly ash geopolymers (WFA) due to the pre-depolymerization implemented by wet-milled mechanical forces, and coupled with the activation effect of CH to improve the depolymerization efficiency and condensation reaction. The compressive strength of WF-CH-19 was three times higher than that of FA-CH-19, reaching 29.3 MPa at 28 d, and the compressive strength growth of WF-CH-11 even reached 591.67% at 1 d. Meanwhile, the main chain length (MCL) and Al/Si of calcium silicate hydrates were clearly improved, and pore structure was significantly refined with capillary pore increased from 29.79% to 89.23%. In addition, FA and WFA geopolymers have significant advantages over Portland cement in the environmental impact indicators such as E-energy and E-CO2. (C) 2022 Elsevier Ltd

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20100 - Civil engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Journal of Cleaner Production

ISSN

0959-6526

e-ISSN

1879-1786

Svazek periodika

372

Číslo periodika v rámci svazku

October 2022

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

39

Strana od-do

nestrankovano

Kód UT WoS článku

000911719600003

EID výsledku v databázi Scopus

2-s2.0-85137060814