Evaluation of air-foam stabilized soil of dredged soil waste as a pavement subgrade layer

Abstract

Air-foam stabilized soil is a kind of waste soil treated with cement and air-foam to make it durable and slight. It has been used widely in geotechnical applications; however, applying in subgrade layer of pavement has not considered. The purposes of this study are the followings: a) the strength properties based on the stress-strain behaviors, b) the durability by simulating the Freeze-Thaw Cycle (FTC), c) thermal conductivity test, and d) the evaluation of pavement performance when the air-foam stabilized soil was used as the subgrade layer. From the results of experiments, it is observed that the strength of air-foam stabilized soil increased with an increase in cement content, but decreased with increasing air-foam content or number of FTCs. The thermal conductivity of air-foam stabilized soil decreased with increasing air-foam content. The resilient modulus of air-foam stabilized soil was determined from the repeated load triaxial test to predict the fatigue and rutting life of the pavement according to AASHTO T 307. The testing results were compared with specification of the Korean pavement design life, and it showed that air-foam stabilized soil is suitable to be used as subgrade material to enhance its properties, and reduce damages such as fatigue cracking and rutting.