Modification of subgrade properties using waste material

This paper covers using of waste glass bottles to modify the properties of poor subgrade soils. The study involved grinding of waste glass bottles into powder in two categories based on the size of particles: category S1 includes particles between 425µm and 75µm whereas category S2 includes particles finer than 75µm. For both categories, five different contents of glass powder were added to a selected soil to investigate their effects on its engineering properties. The results exhibited that increase in glass powder content increases the strength of subgrade soil and decreases its volume change susceptibility. However, using S2-powder revealed better results than those attained using S1-powder. Compared to unmodified soil, maximum dry density, resilient modulus, and CBR values of soils modified using 20% of S2-glass powder increased to 112%, 394%, and 853% respectively whereas the values of liquid limit, plasticity index, optimum moisture content, and swelling ratio decreased to 85%, 68%, 80% and 51% respectively.