Impact of the mineralogy of low–purity clays on their suitability as supplementary cementitious materials

Ilda Tole; Yuvaraj Dhandapani; Simon Kemp; Alastair Marsh; Clive Mitchell; Leon Black; Hong Wong; Susan Bernal Lopez

doi:10.1016/j.cemconres.2026.108211

Impact of the mineralogy of low–purity clays on their suitability as supplementary cementitious materials

Ilda Tole, Yuvaraj Dhandapani, Simon Kemp, Alastair Marsh, Clive Mitchell, Leon Black, Hong Wong, Susan Bernal Lopez

Research output: Contribution to journal › Article › peer-review

Abstract

The lack of rapid screening and selection criteria limits the use of low–purity and common clays as supplementary cementitious materials (SCMs). Here the potential suitability as SCMs of 73 clays from 27 different geological formations, was investigated. Neither chemical composition nor kaolinite content were appropriate criteria to infer the calcined clays pozzolanic reactivity, which is the recommendation in existing guidelines. Clays exhibiting a total clay mineral content of ≥40 wt%, and a mica content below 60 wt% in the clay mineral fraction present moderate to high pozzolanic reactivity when calcined at 800 °C. Low–purity clays derived from kaolinitic Carboniferous formations, such as the Etruria and Pennine Coal Measures, consistently exhibited higher pozzolanic reactivity, compared with younger or marine–derived clays, particularly those from Jurassic, Cretaceous, and Quaternary aged-units. This new knowledge provides a novel guideline for the exploration and sourcing of promising clays for SCMs production globally.

Original language	English
Article number	108211
Journal	Cement and Concrete Research
Volume	204
Early online date	20 Mar 2026
DOIs	https://doi.org/10.1016/j.cemconres.2026.108211
Publication status	E-pub ahead of print - 20 Mar 2026

Data Availability Statement

The database of this study is available in http://doi.org/10.5281/zenodo.18406772. For information about specific clay’s locations please contact Dr. Clive Mitchel [email protected], and Dr. Simon Kemp [email protected]

Acknowledgements

This study was sponsored by the UK Engineering and Physical Sciences Research Council (EPSRC) via the project ‘Engineering UK clays for production of low–carbon cements’; through the awards EP/W021811/1, EP/W022583/1, EP/W021765/1. SJK and CJM publish with the permission of the Director of the BGS (UK Research and Innovation). Participation of S.A. Bernal in this study was also sponsored by EPSRC through the grant EP/R001642/1. The authors are grateful to the clay source owners for their valuable donation of samples, making this study possible. We also acknowledge the valuable discussions and comments from the industry partners and supporters of this project, which helped us to analyse the results considering practical needs for the widespread uptake of low–purity clays in industrial practice.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 14 Life Below Water

Access to Document

10.1016/j.cemconres.2026.108211Licence: CC BY

Cite this

@article{19bcbb9bd3f046f2b2faa77dfedcacac,

title = "Impact of the mineralogy of low–purity clays on their suitability as supplementary cementitious materials",

abstract = "The lack of rapid screening and selection criteria limits the use of low–purity and common clays as supplementary cementitious materials (SCMs). Here the potential suitability as SCMs of 73 clays from 27 different geological formations, was investigated. Neither chemical composition nor kaolinite content were appropriate criteria to infer the calcined clays pozzolanic reactivity, which is the recommendation in existing guidelines. Clays exhibiting a total clay mineral content of ≥40 wt\%, and a mica content below 60 wt\% in the clay mineral fraction present moderate to high pozzolanic reactivity when calcined at 800 °C. Low–purity clays derived from kaolinitic Carboniferous formations, such as the Etruria and Pennine Coal Measures, consistently exhibited higher pozzolanic reactivity, compared with younger or marine–derived clays, particularly those from Jurassic, Cretaceous, and Quaternary aged-units. This new knowledge provides a novel guideline for the exploration and sourcing of promising clays for SCMs production globally.",

author = "Ilda Tole and Yuvaraj Dhandapani and Simon Kemp and Alastair Marsh and Clive Mitchell and Leon Black and Hong Wong and \{Bernal Lopez\}, Susan",

year = "2026",

month = mar,

day = "20",

doi = "10.1016/j.cemconres.2026.108211",

language = "English",

volume = "204",

journal = "Cement and Concrete Research",

issn = "0008-8846",

publisher = "Elsevier",

}

TY - JOUR

T1 - Impact of the mineralogy of low–purity clays on their suitability as supplementary cementitious materials

AU - Tole, Ilda

AU - Dhandapani, Yuvaraj

AU - Kemp, Simon

AU - Marsh, Alastair

AU - Mitchell, Clive

AU - Black, Leon

AU - Wong, Hong

AU - Bernal Lopez, Susan

PY - 2026/3/20

Y1 - 2026/3/20

N2 - The lack of rapid screening and selection criteria limits the use of low–purity and common clays as supplementary cementitious materials (SCMs). Here the potential suitability as SCMs of 73 clays from 27 different geological formations, was investigated. Neither chemical composition nor kaolinite content were appropriate criteria to infer the calcined clays pozzolanic reactivity, which is the recommendation in existing guidelines. Clays exhibiting a total clay mineral content of ≥40 wt%, and a mica content below 60 wt% in the clay mineral fraction present moderate to high pozzolanic reactivity when calcined at 800 °C. Low–purity clays derived from kaolinitic Carboniferous formations, such as the Etruria and Pennine Coal Measures, consistently exhibited higher pozzolanic reactivity, compared with younger or marine–derived clays, particularly those from Jurassic, Cretaceous, and Quaternary aged-units. This new knowledge provides a novel guideline for the exploration and sourcing of promising clays for SCMs production globally.

AB - The lack of rapid screening and selection criteria limits the use of low–purity and common clays as supplementary cementitious materials (SCMs). Here the potential suitability as SCMs of 73 clays from 27 different geological formations, was investigated. Neither chemical composition nor kaolinite content were appropriate criteria to infer the calcined clays pozzolanic reactivity, which is the recommendation in existing guidelines. Clays exhibiting a total clay mineral content of ≥40 wt%, and a mica content below 60 wt% in the clay mineral fraction present moderate to high pozzolanic reactivity when calcined at 800 °C. Low–purity clays derived from kaolinitic Carboniferous formations, such as the Etruria and Pennine Coal Measures, consistently exhibited higher pozzolanic reactivity, compared with younger or marine–derived clays, particularly those from Jurassic, Cretaceous, and Quaternary aged-units. This new knowledge provides a novel guideline for the exploration and sourcing of promising clays for SCMs production globally.

U2 - 10.1016/j.cemconres.2026.108211

DO - 10.1016/j.cemconres.2026.108211

M3 - Article

SN - 0008-8846

VL - 204

JO - Cement and Concrete Research

JF - Cement and Concrete Research

M1 - 108211

ER -

Impact of the mineralogy of low–purity clays on their suitability as supplementary cementitious materials

Abstract

Data Availability Statement

Acknowledgements

UN SDGs

Access to Document

Fingerprint

Cite this