Engineering Characteristics of Cement-Stabilized Lateritic Soils for Highway Construction

Abstract

Rock aggregates are major construction materials globally. However, high cost, scarcity, environmental problems, and depletion of natural resources associated with the production of crushed rocks for subbase and base courses have necessitated search for alternative available quality materials for sustainable highway pavement construction. Cement was added to lateritic soils at varying percentages of 2, 4, 6, 8, and 10%. The soil–cements were subjected to various laboratory tests to establish their potentials for use as pavement layers instead of crushed rocks for economical and environmental sustainability. In addition, CBR, UCS of the soil–cements (cured for 7 and 14 days), and the percentage of cement model were used to establish a second-order polynomial to correlate the soil–cement mix. Compaction results showed a decrease in maximum dry density and an increase in optimum moisture content. California bearing ratio (unsoaked CBR and soaked CBR) and unconfined compressive strength (UCS) values of the cement-stabilized lateritic soils cured for 7 and 14 days increased with higher cement contents up to 8%, after which there were reductions in CBR and UCS. The strength of the soils does not only depend on cement content, but also on the soil curing period. The obtained improved strength indices allow a reduction in the pavement thickness at a low cost of road construction. The polynomial model was found to predict good relationships between strength indices and the percentage of the cement used. 8% by the soil weight of the cement. The stabilized lateritic soils could be used as potential subbase and base materials for highway construction.