Abstract
This study investigated the regression analysis of tropical soil (TS) stabilised with calcium chloride salt (CCS) using the Standard Proctor Method (SPM) to assess its suitability as a pavement construction material. Laboratory tests, including Atterberg limits (liquid limit, plastic limit, and plasticity index) and compaction parameters (maximum dry density, MDD; optimum moisture content, OMC), were conducted on both natural and stabilised soils in accordance with British Standard Light specifications. CCS was applied at concentrations ranging from 4% to 16%. Results were evaluated using analysis of variance (ANOVA) and regression analysis. Findings indicated that increasing CCS content increased the coarseness of the lateritic soil. MDD initially decreased from 1.63 Mg/m³ (untreated) to 1.45 Mg/m³ at 4% CCS, then increased to 1.97 Mg/m³ at 16% CCS, while OMC rose from 19.47% at 4% CCS and declined progressively at higher CCS. Regression analyses confirmed significant differences across most test parameters, except for the plasticity index, which showed no variation. High coefficient values were recorded across treatments. The study concludes that CCS effectively improves the engineering properties of tropical soils and recommends close monitoring of CCS content and liquid limit parameters during pavement design for low-traffic road applications.