Analisis Kuat Dukung Tanah Lempung Bayat Klaten dengan Bahan Stabilisasi Serbuk Bata Merah dan Gypsum

A soil is one of the supporting parts in the construction of a building. Clay is a type of soil that is cohesive, plastic, and has a low bearing capacity. Climatic and geographical conditions are also very influential in clay conditions. There are many ways to stabilize the soil, one of the examples is by adding red brick powder and gypsum as a stabilizing material. The mixture of red brick powder and gypsum can increase the bearing capacity. The purpose of this research is to find out the changes of soil physical properties, the value of bearing capacity and swelling soils after stabilization with red brick powder. This research method included a series of soil physical properties tests such as the test of water content, specific gravity, Atterberg limits, soil grain size analysis and soil mechanical properties testing in the form of standard Proctor and CBR test. Based on the testing of the physical properties of the native soil obtained the water content value 6.145%, specific gravity 2.690, liquid limit 72,60%, plastic limit 33.52%, shrinkage limit 12.85%, and plasticity index 36.65%. Native soil includes A-7-5 group based on the AASHTO, whereas based on the USCS, native soil includes CH group namely clay soil that has high plasticity. The result of the clay physical properties test that was stabilized with 5% gypsum and the red brick powder with a variation of 0%; 2,5%; 5%; 7,5 as well as 10% showed that the value of water content, specific gravity, liquid limit, and the percentage value pass the sieve No. 200 has decreased, while the plastic limit value and the shrinkage limit has increased. The classification of mixed soil, according to the AASHTO included in A-7-5 group, whereas according to the USCS the mixed soil included in MH group, namely inorganic silt soil that has a high plasticity. The soil with a mixture of 10% has the highest dry density, the smallest optimum water content obtained at the mixture of 10% with the value 1.49 gr/cm3 and 34.32%. The highest soaked CBR value was 7% and unsoaked CBR value was 30% at the mixed soil of 10%. The swelling value has decreased by 0.636% in 10% mixture due to the increasing percentage of the mixture