Experimental Study of Silty Soil Using Gypsum and Cement on California Bearing Ratio (CBR)

Abstract

Merauke Regency is a lowland area, with soft soil conditions that dominate and urgently need to be stabilized. The purpose of this study was to determine the use of a mixture of cement and gypsum as a stabilizing agent. This research uses laboratory experimental methods. The tests carried out are physical and mechanical properties testing. Laboratory CBR is used to determine the value of the increase in CBR on the original soil and soil that has been mixed with cement and gypsum variations. Based on the results of testing the physical properties of the grain fraction for silt of 85.88%, in the calcification using the AASHTO method this soil is included in group A-5 with a description of silt soil with high plasticity. From the results of the tests carried out the CBR value on silt soil is 2.62% while the CBR value of stabilized soil with a percentage of 100% silt + 2% cement + 4% gypsum is 23.54%; 100% silt + 2% cement + 8% gypsum that is 24.41%; 100% silt + 2% cement + 12% gypsum ie 27.02%; 100% silt + 2% cement + 16% gypsum ie 30.51%; and 100% silt + 2% cement + 20% gypsum that is 31.38%. From the CBR value, it can be concluded that the variation increased with each addition of cement and the percentage of gypsum.