Mechanical properties of dredged soil reinforced with natural pozzolan and shredded tires

The utilization of waste materials is still an interesting subject to investigate. The dredged soil (DS) was classified as a waste material that requires more effort to improve its mechanical properties. Adding natural pozzolan (NP) material and shredded tires (ST) can be an exciting field to investigate and quite friendly to the environment. This research objective investigates the mechanical properties of the dredged soil stabilized with natural pozzolan material and shredded tires as a new way of green engineering. This research involved trass as a natural pozzolan and shredded tires as car-used tires waste retreading factory. Basic and mechanical properties tests were investigated, including standard proctor, unconfined compressive strength (UCS), and direct shear of the stabilized dredged soil. The proportions of involved trass were 3%, 6%, 9%, and 12%, while the proportions of shredded tires were 2% and 3% to the maximum dry weight of the material sample. These mechanical properties tests were conducted in a curing period of 7, 14, and 28 days. This recent research shows an increase in the maximum dry weight of the stabilizing soil to the untreated soil by 0.5% - 1.7%. While for the compressive strength value, an increase in the UCS value by 175% - 324% was revealed. Furthermore, there was an increased shear strength value, and it was found that the increase in cohesion value (c) was 6% - 83%, and the increase in internal friction angle value (ϕ) was 31% - 98%.