Kajian Efektifitas Semen Dan Fly Ash Dalam Campuran Soil Cement Memakai Tanah Lempung Dan Pasir Pulau Timor

. Soil cement is result of mixing soil, cements and water, that with level of certain compaction will make a new material mixture, soil cement, which because of it is strength, resistance characteristic to by water, hot and other weather influence is very good as a foundation layer under from road pavement structure. Usage of Fly Ash alternatively material for stabilization can mixture addition Soil Cement. This research done at some testing steps, where at step first is done static testing to the mixture, for example experiment UCS (Unconfined Compressive Strength). Result of testing indicates that Soil Oelmasi (Island Timor) can be classified as Inorganic Clay Soil with high plasticity (CH), Clay Soil Type (A-7-5), Value activity (A) = 1,30 (Aktif Clays) and has Swelling Potential Very High and mineral content Kuarsa (Quartz). In general, 5% - 15% cements shows number optimum of decrement Plastisitas Index (PI). While 3% - 7% fly ash can increase value Plastisitas Index(PI). Decrement and addition Plastisitas Index (PI) be an transformation indicator of strength from soil Clay Anorganic (CH). Addition of 13%semen curing of 28 days value Unconfined Compressive Strength (UCS) optimal that is = 12,59 Kg/Cm2. For Soil Bolok (Island Timor) be type Sand good gradation (SW), soil sands type (A-1-b) with content mineral calcite. Addition cement 10 % can increase value UCS so reaching optimal value 21,87 kg/cm2 at the curing of 28 days