The Effect of Limestone and Fly Ash on Clay Stabilization on CBR and Soil Compressive Strength

Abstract

The subgrade in the road access construction project must have a strong soil bearing capacity so that it can withstand the load on it. Clay soil has high water content and expands easily. Various ways have been done to overcome it, one of them is by improving the original soil properties using the stabilization method. The research conducted is the stabilization of expansive clay soil using fly ash and limestone with a percentage of fly ash 5%, 10%, 15%, 20% fly ash and 25% limestone. Existing soil used from a wellpad construction project, in Ujung Pangkah, Gresik, East Java. The tests carried out are specific gravity, Atterberg, compaction, CBR and UCT tests. The CBR test was conducted to determine the appropriate CBR value to support DDT. The compressive strength of the soil was tested using the UCT test. The results of the study of the effect of fly ash and limestone are an increase in the dry weight of the soil and a decrease in soil water content. The increase in CBR and maximum soil compressive strength with a mixture variation of 20% fly ash + 25% limestone, Qu is 2.98 kg/cm 2 and CBR is 10.56%. This is due to a decrease in the water content thereby increasing the dry weight of the soil.