AI Summary & Key Takeaways
AI InsightThe test results indicated that liquid limit (LL), plasticity index (PI) and swelling potential of the soil decreased steadily with increasing molar concentrations of NaOH solution.
📌 3 Key Takeaways
Abstract
Expansive clay subgrades are problematic soils encountered in road construction and should be treated appropriately. In this study, the stabilization of the expansive subgrade with sodium hydroxide (NaOH) was investigated. The effect of NaOH with different molarities (8M, 12M and 15M) on the properties of expansive subgrade was evaluated by performing consistency, free swell, compaction, unconfined compressive strength (UCS) and California bearing ratio (CBR) tests at three different curing durations of 1, 7 and 28 days. The test results indicated that liquid limit (LL), plasticity index (PI) and swelling potential of the soil decreased steadily with increasing molar concentrations of NaOH solution. The soil's maximum dry density (MDD) and the optimum moisture content (OMC) increased consistently with the NaOH solution. An approximately 150% and 285% increase in the UCS and CBR values of the pure soil after 28 days of curing was achieved with a 15 M NaOH solution. The present study has yielded encouraging results with regard to the sustainability of stabilizing expansive clayey subgrades through the use of NaOH.