Strengthening and Supporting Efforts to Reduce Swelling of Soil by Using Beach Sands Through CBR Test

Many roads are damaged due to heavy tonnage vehicles or because the road foundation is in the form of expansive clay. The rescue effort is to use beach sand (sea sand) for stabilization / repair of road sub-grade in the form of clay. This research using experimental method to carried out by repairing/stabilizing soil clay by mixing beach sand. Sand content varies from 60%, 80%, to 100%. Mixed soil was compacted at optimum water content, then tested by CBR test and Swelling test. The results of this study are CBR (strong-support) and Swelling (development) values. Mixing: 60%, 70%, 80%, 90%, 100% beach sand against clay, able to increase the CBR value by a row: 7.3%; 9.6%; 11.8%; 18.5%; 25.2% (Lendah clay, Unsoaked), and 6.2%; 9.8%; 13.4%; 19.3%; 25.2% (Lendah clay, Soaked). The Prambanan clay, the yield is slightly smaller than the Lendah clay. The Swelling value is: 0.095%; 0.055%; 0.015%; - 0.107%; -0.229% (Lendah clay), almost the same as Prambanan clay. Here it can be seen that mixing beach sand will always increase the CBR value, but if the percentage of sand is too much, the soil will easily collapse (negative swelling). The conclusion is that in the clay mixture with beach sand the optimum percentage of beach sand will be 85%.