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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

<a href="/en/project/GA22-16577S" target="_blank" >GA22-16577S: Alternatives of thermally activated lower grade clays as a partial cement replacement</a><br>

Continuities

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

Publication year

2025

Confidentiality

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

Name of the periodical

Journal of Building Engineering

ISSN

2352-7102

e-ISSN

2352-7102

Volume of the periodical

106

Issue of the periodical within the volume

July

Country of publishing house

GB - UNITED KINGDOM

Number of pages

21

Pages from-to

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UT code for WoS article

001476211100001

EID of the result in the Scopus database

2-s2.0-105002863754