PENGARUH WAKTU PEMERAMAN TERHADAP SIFAT FISIS DAN MEKANIS TANAH EKSPANSIF STABILISASI KAPUR MODIFIKASI ABU VULKANIK KELUD

Expansive soils are fine-grained soil types that have a high plasticity index, low carrying capacity, and is sensitive to changes in water content so that the nature and development of shrink and swell. This is very disserve when expansive soil is used as a basic building construction. To overcome this stabilization needs to be done on the ground as a basic construction. This stabilization is utilizing on Kelud volcanic ash combined with lime. This study conducted by mixing soil stabilization material original to be three and four variations of curing time. A mixture of ash, respectively 15%, 20%, 25% and 5% lime to soil dry weight. For a long curing time used 1, 3, 7, and 14 days. The tests were the soil physical properties test and the soil mechanical properties test . The results of the research on native soil mixed with volcanic ash and lime showe that the addition of vulcano ash and curing time can degrade the soil plasticity index, the value of the permeability coefficient and mix soil cohesion, while the value of the shear angle increases. The soil physical properties is known the variation of 25% Kelud ash + 5% lime impaired greatest plasticity index with curing period of 14th days. On the permeability variation test 15% Kelud ash + 5% lime impaired greatest permeability coefficient with 14th days curing period. In soil shear strength test variations 25% Kelud ash + 5% lime increase the value of friction angle with 14th days curing time