Shear Strength Stabilization Using Burned Sludge Ash
This research studied the potential use of burned sludge ash to improve the shear strength parameters of clayey soils. The sludge ash was obtained by burning the sludge at 550 °C. Two types of clay soils were used in this study and the initial physical properties such as Atterberg’s limit, gradation, compaction parameters were determined. The selection of the soils was based on plasticity index and clay fraction. The sludge ash was mixed with the soil at different percentages by dry weight of the soil at 2.5% increment. Standard Direct shear test (ASTM-D3080) was conducted on specimen mixed with sludge ash. The results showed that the increase in the sludge ash up to 7.5% will increase both the cohesion and angle of internal friction. Further increase of the sludge ash will reduce both the angle of internal friction and the cohesion in the two soils. However highly plastic clay soil (CH) shows a higher increase in the percentages of the shear strength parameters than low plastic soil (CL) for the same percentages of the burned sludge. The result of this research implies that sludge ash can be used to stabilize the soil and further reduce the environmental hazard associated with this material.
Keywords- Soil, Sludge Ash, Shear Strength, Cohesion, Clay