Efektifitas Gipsum Sebagai Bahan Stabilisasi Terhadap Nilai Penurunan Konsolidasi Subgrade Jalan Sukodono Sragen

Based on the results of previous studies conducted by Prasetyo(2016) land Sukodono Sragen has a value of PI = 61.04%, which included a high plasticity clay soils, it is necessary to repair the ground. The purpose improvement of the soil is improving of soil physically and mechanic as properties to use for contruct of building or pavement. Improvements made by means of chemical stabilization using gypsum with a percentage of 0%, 2.5%, 5%, 7.5% and 10% of the weight of the sample. The test methods include testing the physical properties and mechanical properties of native soil and soil mix. The result of the physical properties of the native land and the increasing percentage of ground gypsum mixture water content, liquid limit, shrinkage limit, plasticity index and sieve 200 declined while the value of specific gravity and the plastic limit increase. Classification according to AASHTO clay with gypsum percentage of 0%, 2.5%, 5%, 7.5% and 10% belongs to a group of A-7-6, while according to the USCS included in the group CH. The test results of mechanical properties Standard Proctor native soil and soil mix dry volume weight obtained maximum value increased while the value of the optimum moisture content decreased. The value of weight dry volume to a maximum of 1.324 g / cm3 and the lowest optimum moisture content of 23.5% in the soil mix percentage of 10%. The test results showed that the increasing consolidation of the gypsum percentage consolidation coefficient (Cv) increased while the value of compression index (Cc) and a decrease of consolidated (Sc) decreased. The highest Cv value of 0.0170 cm2 / sec, Cc values as low as 0.165 and the lowest value of 0.0658 cm Sc obtained at 10% ground gypsum mixture. Keywords: gypsum, consolidation, stabilization, cla