Formulation and Evaluation of an Aloe Vera–Based Hybrid Soil Stabilizing Agent Incorporating GGBS and Cement for Base Course Improvement

This study evaluates a sustainable hybrid stabilizer—cement, GGBS, and Aloe vera—for improving pavement base courses while lowering carbon emissions. Lab and field testing on well-graded A-2-4(0) soil assessed physical and mechanical properties, with data analyzed via one-way ANOVA and Tukey’s HSD. Higher stabilizer concentrations improved particle packing in four mixtures (T0 to T3), increasing maximum dry density while decreasing optimum moisture content. Visual monitoring revealed that while increased GGBS content led to desiccation in T1 and T2, the additional 0.2% Aloe vera dosage in T3 successfully maintained a moist matrix through enhanced moisture retention. Consequently, one-way ANOVA and Tukey’s HSD confirmed statistically significant CBR leaps across all design transitions (p<0.05). CBR values escalated from 36.23% in untreated soil (T0) to a peak of 205.05% in T3, driven by high dosage sensitivity between T1 and T2 (Δ=61.97%) and moisture-retention efficacy between T2 and T3 (Δ=57.96%). Ultimately, both T2 (147.10%) and T3 cleanly exceeded the DPWH 100% minimum base course requirement. Although the T3 mixture demonstrated the best overall performance, the T2 mixture is the best option for real-world projects, reducing standard cement consumption by 21% to maximize material efficiency.