INFLUENCE OF BIOCHAR WATER HYACINTH ON THE SHEAR STRENGTH OF ULTISOLS

Abstract

Ultisols are reddish, acidic and clayey soils which are abundant in the Philippines. It is commonly found in upland areas and approximately covers 41.5% of the land area. However, this material is underutilized due to its high plasticity which can have an adverse effect to its shear strength. In order to explore ultisol’s potential, soil stabilization is essential. A promising material that can be blended to ultisol is water hyacinth biochar. This type of material has hydrophobic qualities which can be beneficial to high plastic material since it can repel water. Water hyacinth was used since it is an invasive species that disrupts the bodies of water that it grows on. In this study, biochar water hyacinth was blended to ultisols having 0%, 5% and 10% proportions. To investigate on the influence of this material to ultisols the relative density was varied. The samples were prepared having a relative density of 32.5%, 60% and 92.5%. The shear strength parameters were established by performing a direct shear test under undrained condition. Based on the results, biochar water hyacinth had a significant effect on the cohesion of the soil.