ROLE OF FLY ASH ON GEOTECHNICAL PROPERTIES OF CLAYEY SOILS

Abstract

Geotechnical investigation plays a fundamental role in building stable infrastructure. Soil stabilization is a primary element in focus for the development of durable infrastructure. Clayey soils are more problematic as they show considerable volume change. They become hard in the dry state while their strength is decreased in the wet state. This behavior results in a decrease in the stability and durability of any infrastructure. This research is conducted to overcome the problems and to observe the change in behavior of clayey soils of Hassan Abdal area by the addition of fly ash. An attempt was made by adding various fly ash proportions i.e., 5%, 10%, 15%, 20%, 25% and 30%. A variety of laboratory tests are performed. To generate the PI trend with varying fly ash percentages, liquid limit and plastic limit tests are conducted. Maximum dry density (MDD) and optimum moisture content (OMC) are obtained from the proctor compaction test. OMC is added to the clayey soil to perform CBR test to find the load bearing capacity of soil as subgrades. The results showed that PI decreases by adding fly ash up to 10%. Under soaked conditions, the CBR values increase up to 10% of fly ash and decline afterward. Thus, the addition of fly ash in clayey soils can enhance its geotechnical properties.