RT Journal Article
T1 Low-grade kaolinitic clays as SCMs for low-carbon cements and strength improvement by C-S-H gel nucleation seeding
A1 Vallina, Diego
A1 Santacruz-Cruz, María Isabel
A1 Morales-Cantero, Alejandro
A1 Rodríguez-Ruiz, María Dolores
A1 Cuesta, Ana
A1 Gómez-de-la-Torre, María de los  Ángeles
A1 Dalla-Libera, Alessandro
A1 Borralleras, Pere
A1 Dhers, Sébastien
A1 Schwesig, Peter
A1 Mazanec, Oliver
A1 García-Aranda, Miguel Ángel
K1 Resistencia de materiales
K1 Cemento
K1 Arcilla
AB This study seeks to push the limits of LC3-50 binders by utilising low-grade kaolinite clays and C-S-H gelnucleation seeding. Four commercially-available kaolinite clays (i.e. kaolinite contents ~20 wt%) have been studied by X-ray fluorescence, X-ray powder diffraction and thermal analysis. The clays were thermally activated and milled to Dv,50 = 11 ± 2 μm. The activated clays showed low pozzolanic performances, as determined by ASTM C1897-20 standard. The heat flows ranged 200–230 J/g calcined clay and the bound waters 4.3–5.7 %.The LC3-50 pastes were characterised by calorimetry, X-ray powder diffraction and the Rietveld method, thermal analysis, and porosimetry to evaluate pozzolanic reactivity and the seeding effect.LC3 mortars, w/b = 0.40, have relatively low compressive strengths, especially at one day, but these values were increased by 64 % on average at one day by seeding. At 1 day, three LC3 mortars showed 11 MPa which increased to 18–20 MPa by seeding. A fourth mortar showed a much higher compressive strength, 16 MPa, that increased to 23 MPa, by seeding. A tested concrete, w/b = 0.50, also showed a high increase of 37 % at 1 day.The improvements at 28 days were maintained but quantitatively lower, 12 and 14 % for the mortars and the concrete, respectively. Insights into the pozzolanic reactions and C-S-H seeding are obtained from the quanti-tative study of the pastes. For instance, it is proven the pozzolanic reaction at 1 day from the portlandite con-sumption. Also shown is the enhanced formation of carboaluminates when the strength enhancing admixture is added.
PB Elsevier
YR 2026
FD 2026-01
LK https://hdl.handle.net/10630/40471
UL https://hdl.handle.net/10630/40471
LA eng
NO Diego Vallina, Isabel Santacruz, Alejandro Morales-Cantero, María Dolores Rodríguez-Ruiz, Ana Cuesta, Angeles G. De la Torre, Alessandro Dalla-Libera, Pere Borralleras, Sébastien Dhers, Peter Schwesig, Oliver Mazanec, Miguel A.G. Aranda, Low-grade kaolinitic clays as SCMs for low-carbon cements and strength improvement by C-S-H gel nucleation seeding, Cement and Concrete Research, Volume 199, 2026, 108036, ISSN 0008-8846, https://doi.org/10.1016/j.cemconres.2025.108036.
NO Artículo disponible online desde 24/09/2025
NO Funding for open access charge: Univ. Málaga/CBUA.
NO PID2020-114650RB-I00 grant from Ministry of Science and Innovation of Spain, co-funded by ERDF, is gratefully acknowledged. D. Vallina thanks Ministry of Science and Innovation of Spain (PRE2021-099053 doctoral grant). The Escuela de Ingenierías Industriales (Univ. Malaga) is also gratefully recognised, as the mechanical properties were measured there (facility funded by Junta de Andalucía and ERDF (IE19_182 UMA grant))
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 23 ene 2026