EVALUATION OF FLY ASH AND RICE HUSK ASH ON THE UNCONFINED COMPRESSIVE STRENGTH OF THE COMPACTED CEMENT TREATED LATERITIC SOIL

The unconfined compressive strength (UCS) and modulus of elasticity characteristics for stabilized soil are required in many geotechnical applications. This work aimed to investigate the potential of Fly ash (FA) and Rice Husk ash (RHA) as cement replacement in soil stabilization of the lateritic soil for materials used in pavement applications. The specimens were compacted under modified Proctor at optimum water content. The cement content was varied from 1 to 3%, the percentage of ash replacement was varied from 10 to 30%. A series of UCS tests are carried out after 28 days of curing. To investigate deformation response, the Local Deformation Transducer (LDT) and the Linear Variable Differential Transformer (LVDT) were used to measure the deformation of the specimens. By considering the UCS value, the amount of RHA at 10-30% replaced effectively to the 1-2% cement mixed lateritic soil without reducing the mixing strength. Satisfactory performance of FA was observed at only 1% cement mixture. The modulus measured by both the LVDT and LDT has linear relations with the strength. The empirical expressions for predicting the strength of cement and cement-ash treated are used to characterize the influences of mixing ratio on the strength of cement-ash treated lateritic soil. The efficiency factor and effective void ratio concepts are reasonable to predict the strength of cement-ash treated lateritic.