TITLE:
Assessing the Suitability of Zimado Clay as a Precursor for Sustainable Lightweight Expanded Clay Aggregate (LECA) Production
AUTHORS:
Abraham Zigla Atour, Darman Japhet Taypondou, Hippolyte Todou Assaouka, Pieride Mabe Fogang, Vincent de Paul Zoua, Patrick Mountapmbeme Kouotou, Etienne Yanné
KEYWORDS:
Conventional Aggregates, Zimado Clay, Lightweight Aggregates, Characterization, Thermal Treatment, Bloating Criteria
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.14 No.8,
August
11,
2026
ABSTRACT: The supply of conventional aggregates represents a well-established major challenge in several landlocked localities of the Lake Chad Basin, particularly in the Zimado area, where such materials are typically sourced from quarries located at considerable distances. In response to this constraint, the present study aimed, for the first time, to carry out a comprehensive physical, chemical and mineralogical characterization of Zimado clay, with a view to assessing its thermal expansion potential for the production of lightweight aggregates via heat treatment. Three representative samples (ZC1, ZC2 and ZC3) were collected at a depth of 70 cm to ensure adequate spatial representativeness. These samples were subjected to particle size analysis (NF P 94-056/057), Atterberg limit determination (NF P 94-051) and absolute density measurement, alongside geochemical and mineralogical analyses including X-ray fluorescence (XRF), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The results reveal that Zimado clay exhibits a silty-clayey texture, with silt and clay fractions accounting for 41.41% and 24.84%, respectively, a moderate plasticity index ranging from 15.68% to 23.12%, and a mean absolute density of 2.409 g/cm3. The chemical composition is predominantly aluminosilicate in nature, with SiO2 contents ranging from 63.06 to 65.90 wt% and Al2O3 from 14.94 to 15.60 wt%. The mineralogical assemblage is dominated by quartz, kaolinite, illite, feldspars and ferruginous phases. Assessment against Riley’s (1951) expansion screening criteria indicates that two of the three compositional thresholds are met by the measured composition; only the total flux oxide content (~10.55 - 11.78 wt%) falls marginally below the recommended minimum of 13 wt%. Collectively, these results provide a first baseline characterization of Zimado clay and support its preliminary identification as a physicochemical promising precursor for lightweight expanded clay aggregate production; empirical validation through firing trials remains necessary before production suitability can be confirmed.