Assessment of Index Properties and Compaction Characteristics of Heat-Treated Laterite for Rural Road Pavement Construction

Abstract

This study assessed the impact of heat treatment on the index properties and compaction characteristics of lateritic soils for rural road pavement construction. Four lateritic soils sourced from MGA, MGC, MGB, and Yogbo Road were subjected to heat treatments at varying temperatures of 50°C, 100°C, 150°C, and 200°C. The Atterberg limits, specific gravity, maximum dry density (MDD), and optimum moisture content (OMC) of the samples were analyzed. The results indicated a significant reduction in plasticity (liquid limit, plastic limit, and plasticity index) as heat treatment temperatures increased, with the most notable reductions observed up to 100°C. Beyond 150°C, the soils exhibited minimal further improvement, and at 200°C, some soils, particularly soils from MGA and Yogbo Road, became non-plastic. MDD values improved up to 100°C, with a peak of 2.28 g/cm³ for Yogbo Road soil, after which MDD values plateaued or slightly declined. Specific gravity values varied, with a significant increase at 200°C for most soils. The findings suggest that controlled heat treatment can enhance the suitability of lateritic soils for rural road pavement 
construction by improving compaction and reducing moisture sensitivity. Further research on mineralogical transformations for the heat-treated temperatures used in the research and those at higher temperatures is recommended to optimize the heat treatment process for practical applications.