ANALYZED SOIL IMPROVEMENT BASED GYPSUM AND CEMENT IN SOIL CLAY

Land is an important element of the structure underneath a construction, so that the soil must have a good carrying capacity. But the reality on the ground is that many soils have low carrying capacity, so it is necessary to stabilize the soil with gypsum and cement. This study aims to determine the effective percentage of gypsum and cement addition and the effect of the addition of Gypsum and Cement to physical changes in clay soil in terms of the CBR (California Bearing Ratio) value of the curing time. This research was conducted in the laboratory, by testing the physical properties of the soil and the carrying capacity of the soil (CBR) with variations in the addition of gypsum and cement by 1%, 3%, and 5% with a long curing time of 1, 7, and 14 days . Sample testing is carried out with two treatments, namely soil samples are first cured and then compacted and the sample is solidified first and then cured. From the research results obtained the largest CBR (California Bearing Ratio) value occurs in the variation of the addition of Gypsum and Cement 5% with the length of time for soil specimens to be compacted first before curing is equal to 41.54%, this is due to the mixture of soil with gypsum and cement has been manjai solid before the collection can occur, the cavities between soil particles also become solid, so that the strength also increases. From the California Bearing Ratio results, it can be seen that the addition of gypsum and cement to clay soil shows an increase in the value of California Bearing Ratio on clay