Mechanochemical Characterisation of Calcined Impure Kaolinitic Clay as a Composite Binder in Cementitious Mortars

Kwabena Boakye, Morteza Khorami, Messaoud Saidani, Eshmaiel Ganjian, Andrew Dunster, Ahmad Ehsani, Mark Tyrer

    Research output: Contribution to journalArticlepeer-review

    10 Citations (Scopus)
    76 Downloads (Pure)


    The availability of some supplementary cementitious materials, especially fly ash, is of imminent concern in Europe due to the projected closure of several coal-fired power generation plants. Pure kaolinitic clays, which arguably have the potential to replace fly ash, are also scarce and expensive due to their use in other industrial applications. This paper examines the potential utilisation of low-grade kaolinitic clays for construction purposes. The clay sample was heat-treated at a temperature of 800 °C and evenly blended with Portland cement in substitutions of 10−30% by weight. The physical, chemical, mineralogical and mechanical characteristics of the blended calcined clay cement were determined. The Frattini test proved the pozzolanic potential of the calcined impure clay, as a plot of its CaO and OH− was found below the lime solubility curve. The 28 days compressive strengths trailed the reference cement by 5.1%, 12.3% and 21.7%, respectively, at all replacement levels. The optimum replacement level between the three blends was found to be 20 wt.%.
    Original languageEnglish
    Article number134
    Number of pages10
    JournalJournal of Composites Science
    Issue number5
    Publication statusPublished - 6 May 2022

    Bibliographical note

    Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// 4.0/)


    This research was funded by Coventry University under project code 17172-01 and the APC was funded by MDPI open access publishing in Basel/Switzerland.


    • calcination
    • calcined clay
    • compressive strength
    • low-grade kaolinitic clay
    • supplementary cementitious materials

    ASJC Scopus subject areas

    • Ceramics and Composites
    • Engineering (miscellaneous)


    Dive into the research topics of 'Mechanochemical Characterisation of Calcined Impure Kaolinitic Clay as a Composite Binder in Cementitious Mortars'. Together they form a unique fingerprint.

    Cite this