Strengthening the Properties of Clay Soil With Crushed Oysters

When problematic clayey soils are used for engineering purposes without treatment, they can lead to structural cracks in roads, buildings, and underground infrastructure. The use of oyster shell powder in geotechnical applications has been the subject of little research, which is why this study looked into it. Examining the stabilization of different percentages (6, 9, 12, 15, 18, and 21 percent) of oyster shell (OS) treatment of clayey soil is the aim of this study. Compaction, strength, CBR, and Atterberg tests are among the experiments used in this study. The study's importance lies in turning oyster shell waste into a beneficial soil-improvement additive and reducing environmental pollution brought on by the careless disposal of oyster shells, which typically emit an unpleasant stench. The results show that 18% of oyster shell is the perfect percentage to increase the liquid limit by approximately 10% while reducing the plasticity index by 31.4% and increasing in plastic limit, maximum dry density and decreased moisture content. The unconfined compressive strength increased from 40 kPa (soft) for untreated soil to 281 kPa (stiff) at 18% shell content. A verification model with PLAXIS software version 8.2 was used for pavement application under applied traffic loading. It was determined that stabilizing the subgrade soil with oyster shell (18%, 9%) reduced the vertical deformation (rutting) for flexible pavement by roughly (93.5%, 85.8%). Oyster shell alone does not achieve subbase-grade stabilization without additional binders.