Lateritic soils are widely used in sub–Saharan Africa, yet their potential as supplementary cementitious material (SCM) precursors and as bases for unfired compressed stabilized earth blocks (CSEBs) remains under-evaluated. This study assesses four lateritic soils from the Benin City region of Nigeria (BEN1–BEN4) for low carbon binder development and CSEBs. An integrated program combining XRD, XRF, SEM, TGA, geotechnical and mechanical tests was conducted. All soils showed high combined SiO₂-Al₂O₃-Fe₂O₃ contents (81–95 wt%), consistent with natural pozzolanic materials. They were mildly acidic (pH 5.1–6.2) with moderate to high plasticity (PI 16–29%), confirming non-self-cementing behavior. Unstabilized specimens did not meet structural strength requirements, although BEN2 approached minimum cube strength thresholds for earthen blocks. Stabilization with 5–10 wt% Portland limestone cement or NaOH produced major strength gains, yielding unconfined compressive strengths of 2,021–6,495 kPa and cube strengths of 3,013–9,317 kPa. BEN1 showed the strongest SCM potential due to favorable clay mineralogy and oxide balance, while BEN3 and BEN4 required higher binder dosages for CSEBs. NaOH activation enhanced strength but, given cost, handling, and durability concerns, functions mainly as a laboratory reactivity probe rather than a field ready stabilizer. Overall, the findings establish a mineralogical–mechanical basis linking oxide composition, index properties, and binder response. The results indicate that Benin City laterites have strong potential for SCM development and stabilized earth block systems within emerging low carbon construction pathways. This provides a transferable method for evaluating tropical lateritic soils for sustainable construction.
Audu et al. (Wed,) studied this question.