Performance of thermally activated lower-grade clays – The impact of phase composition

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F25%3A00383243" target="_blank" >RIV/68407700:21110/25:00383243 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.jobe.2025.112685" target="_blank" >https://doi.org/10.1016/j.jobe.2025.112685</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jobe.2025.112685" target="_blank" >10.1016/j.jobe.2025.112685</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Performance of thermally activated lower-grade clays – The impact of phase composition

Popis výsledku v původním jazyce

The use of supplementary cementitious materials (SCMs) in concrete production is critical for reducing the carbon footprint of the construction industry. However, the potential of lower-grade clays as SCMs has not been fully explored, and a deeper understanding of their thermal activation is needed to enhance their reactivity and performance in cementitious systems. This paper investigates the thermal activation of lower-grade clays, focusing on the impact of their mineralogical composition. Specifically, six clays differing in the content of clay minerals and the presence of other impurities were thermally activated at four different temperatures (500 °C, 550 °C, 600 °C, 650 °C). Thermal treatment led to the dehydroxylation of clay minerals, which resulted in increased specific surface area. On the other hand, lower-grade clays tend to agglomerate, especially when containing calcite and illite. The amount of amorphous matter and, consequently also the reactivity of lower-grade clays, grow up to 600 °C. However, after exposure to 650 °C, distinct differences between individual clays were observed. Clays containing illite appeared to be overburned, as their performance after 650 °C deteriorated. On the other hand, clays containing calcite calcined at 650 °C showed promising properties in blended cement, outperforming kaolin clay. In addition, it was found that thermally activated lower-grade clays reacted not only with Portlandite (Ca(OH)2) but with other cementitious components as well.

Název v anglickém jazyce

Performance of thermally activated lower-grade clays – The impact of phase composition

Popis výsledku anglicky

The use of supplementary cementitious materials (SCMs) in concrete production is critical for reducing the carbon footprint of the construction industry. However, the potential of lower-grade clays as SCMs has not been fully explored, and a deeper understanding of their thermal activation is needed to enhance their reactivity and performance in cementitious systems. This paper investigates the thermal activation of lower-grade clays, focusing on the impact of their mineralogical composition. Specifically, six clays differing in the content of clay minerals and the presence of other impurities were thermally activated at four different temperatures (500 °C, 550 °C, 600 °C, 650 °C). Thermal treatment led to the dehydroxylation of clay minerals, which resulted in increased specific surface area. On the other hand, lower-grade clays tend to agglomerate, especially when containing calcite and illite. The amount of amorphous matter and, consequently also the reactivity of lower-grade clays, grow up to 600 °C. However, after exposure to 650 °C, distinct differences between individual clays were observed. Clays containing illite appeared to be overburned, as their performance after 650 °C deteriorated. On the other hand, clays containing calcite calcined at 650 °C showed promising properties in blended cement, outperforming kaolin clay. In addition, it was found that thermally activated lower-grade clays reacted not only with Portlandite (Ca(OH)2) but with other cementitious components as well.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/GA22-16577S" target="_blank" >GA22-16577S: Možnosti využití tepelně aktivovaných jílů jako částečné náhrady cementu</a><br>

Návaznosti

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

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Journal of Building Engineering

ISSN

2352-7102

e-ISSN

2352-7102

Svazek periodika

106

Číslo periodika v rámci svazku

July

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

21

Strana od-do

—

Kód UT WoS článku

001476211100001

EID výsledku v databázi Scopus

2-s2.0-105002863754