Improvement of Hnong Han Soil with Natural Rubber and Cement Suitable for Highway Material

Abstract

The objective of this research is to improve the CBR value of Hnong Harn sediment soil to be suitable for highway material. The natural rubber and cement are used to improvement addition. The natural rubber content was at 2.5, 5.0 and 7.5 %, while the cement content was at 4.0, 6.0 and 8.0 % by weight of dry soil.  In case of natural rubber at 2.5 and 5.0 % tended to increase the dry unit weight.  In case of natural rubber content greater than 7.5%, dry unit weight decreases with an increase in the natural rubber.  The CBR value increase with increase of the dry unit weight.  The appropriate content of natural rubber to be in the range of 3.5% - 6.1%.  In the cement-mixed sample that after curing 28 days, the results showed that soil unit weight and CBR increase with an increase of cement content.