Experimental Study on Soil Stabilized with Firming Agent and Lime

In this research, Firming agent (FA) and a small amount of hydrated lime were used to stabilize soil. Five types of soil, 0.2L/m³ of FA, and several low dosages of hydrated lime were selected. Total 15 different soil mixes were studied. The unconfined compressive strength (UCS) of each stabilized soil was tested at the age of 7, 14, 28, and 90 days. Test results show that FA and a low dosage of hydrated lime could effectively stabilize clay soil, but are not suitable for silt. A highly significant linear correlation exists between the UCS of stabilized soil and the cation exchange capacity (CEC) of the soil. The greater the CEC, the higher the strength is. Among the three factors of plasticity index (PI), clay particle content, and CEC, the CEC is themost direct and reliable indicator that reflects whether the soil is suitable for being stabilized with FA and hydrated lime. Minimum criterion of CEC of soil was approximately calculated as 10m mol/kg. If PI is used as a criterion, stabilization results can be ideal when the PI is about 15~ 22.