Performance of Clay-Based Earth Bricks with Varying Sand Content: A Case Study of Lendi Soil, Douala

Authors

  • Ekoum Ewandjo Nkoue

    Laboratory for Mechanics and Materials (LMEMA), National Higher Polytechnic School of Douala, University of Douala, Douala PO BOX 2701, Cameroon
  • Arnold Madouma Madouma

    Ecole Normale Supérieure de l’Enseignement Technique (ENSET) de Libreville, Université Omar Bongo, Libreville PO BOX 3989, Gabon
  • Willy Chance Guimezap Kenou

    Innovation Research Center Entrepreneurship (PRIE), Institut Universitaire de la Cote, Douala PO BOX 3001, Cameroon
  • Roger Eno

    Laboratory for Mechanics and Materials (LMEMA), National Higher Polytechnic School of Douala, University of Douala, Douala PO BOX 2701, Cameroon
  • Fabien Kenmogne

    Department of Civil Engineering, Advanced Teacher Training College of Technical Education, The University of Douala, Douala PO BOX 1872, Cameroon
  • Benjamin Bahel

    Laboratory for Mechanics and Materials (LMEMA), National Higher Polytechnic School of Douala, University of Douala, Douala PO BOX 2701, Cameroon
  • Blaise Ngwem Bayiha

    Department of Civil Engineering, Advanced Teacher Training College of Technical Education, The University of Douala, Douala PO BOX 1872, Cameroon
  • Gilbert Tchémou

    Department of Civil Engineering, Advanced Teacher Training College of Technical Education, The University of Douala, Douala PO BOX 1872, Cameroon
  • Rayane Tiotsop Talonang

    Department of Civil Engineering, Advanced Teacher Training College of Technical Education, The University of Douala, Douala PO BOX 1872, Cameroon
  • Robert Nzengwa

    Laboratory for Mechanics and Materials (LMEMA), National Higher Polytechnic School of Douala, University of Douala, Douala PO BOX 2701, Cameroon

DOI:

https://doi.org/10.30564/jbms.v7i4.11853
Received: 1 September 2025 | Revised: 14 October 2025 | Accepted: 23 October 2025 | Published Online: 28 November 2025

Abstract

This study evaluates the influence of sand content on the mechanical behavior and water resistance of compressed earth bricks (CEBs) manufactured from Lendi clay (Douala, Cameroon). Twenty-seven specimens (prismatic and cubic) were produced with three formulations: 0%, 30% and 60% sand substitution by dry mass, compacted at 2.5 MPa and cured for 7, 14 and 28 days. Raw material characterization included particle size distribution, sand equivalent, Atterberg limits, bulk density and Proctor compaction. The clay displayed a liquid limit of 44.07%, plastic limit of 35.23% and plasticity index of 8.84%; optimum moisture content was 15.9% and maximum dry density 1.24 g·cm⁻³. Mechanical testing showed that pure-clay bricks achieved the highest compressive and flexural strengths at all ages (up to ≈ 1.98 MPa and 0.56 MPa respectively). Although the 30% sand mix exhibited marginally higher early compressive strength (7 days), strength decreased substantially by 28 days. Capillary absorption tests revealed an important distinction: while 0% sand bricks exhibited continuous water uptake, they retained cohesion during immersion; conversely, 30% and 60% sand bricks disintegrated into a slurry within seconds of immersion, evidencing severe loss of internal bonding. These findings indicate that, for this highly plastic tropical clay, sand acts primarily as a microstructural diluent that undermines long-term cohesion and durability despite short-term packing benefits. The study underscores the need for locally tailored formulations or stabilizers when designing durable CEBs for humid tropical climates.

Keywords:

Earth Brick; Clay Soil; Physical Properties; Mechanical Properties; Aggregates

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How to Cite

Nkoue, E. E., Madouma, A. M., Kenou, W. C. G., Eno, R., Kenmogne, F., Bahel, B., Bayiha, B. N., Tchémou, G., Talonang, R. T., & Nzengwa, R. (2025). Performance of Clay-Based Earth Bricks with Varying Sand Content: A Case Study of Lendi Soil, Douala. Journal of Building Material Science, 7(4), 70–83. https://doi.org/10.30564/jbms.v7i4.11853

Issue

Vol. 7 , Iss. 4 (December 2025): In Progress

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Copyright © 2025 Ekoum Ewandjo Nkoue, Arnold Madouma Madouma, Willy Chance Guimezap Kenou, Roger Eno, Fabien Kenmogne, Benjamin Bahel, Blaise Ngwem Bayiha, Gilbert Tchémou, Rayane Tiotsop Talonang, Robert Nzengwa

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This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

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