Pemanfaatan Mill Sebagai Bahan Stabilisasi Terhadap Nilai Cbr Tanah Lempung Desa Nambuhan, Purwodadi, Grobogan

ABSTRACT Many parts of road in Purwodadi are seriously damaged. The damage is caused by the subgrade that cannot support the load of the vehicle passes by. According to Ariyani dan Wahyuni (2007), the subgrade in Puwodadi belongs to inorganic clay with high plasticity. Soil with high plasticity has low resources and high development. Therefore, soil needs to be stabilized to increase its resources. The purpose of clay’s stabilization is to repair physical characteristic and mechanical soil. In this research, the researcher used Califoria Bearing Ratio tool with stabilization percentage of Mill 0%, 3%, 6%, 9% and 12%. It needed care for 0-4 days to conduct mechanical testing. Physical testing consisted of several experiments such as water content, specific gravity (Gs), Atterberg’s limit (liquid limit, plastis limit and shrinkage limit), analysis of grain size (Hydrometer and filter analysis), chemical content of limestone (Mill) at laboratory of analytic chemistry of chemistry department, Mathematic and Science faculty at Gadjah Mada University and standard proctor. From physical characteristic of mixed soil, there was reduction on water content, density, liquid limit, plasticity index and filter pass No. 200. The limit of plasticity and reduction increased. Based on AASHTO method, physical characteristic testing of mixed soil belonged to A-7-5 group. Based on USCS, mixed soil was divided into two groups. Mixed soil with 0% percentage belonged to CH group and 3%, 6%, 9%, 12% percentage belonged to MH group. There was reduction of water content in solidity testing. It was caused by the increase of Mill percentage. In this research, the addition of Mill for 0-4 days did not influence CBR’s value of original soil. CBR’s value of the soil at Nambuhan village was 1%. Keywords: Mill , CBR’s value, care, clay