Mechanical Properties of Soft Clay Soil Improved with Nanomaterials and Chitosan Biopolymer.

Soft clay soil is a concern in geotechnical engineering due to its low strength and high compressibility. Soil improvement with stabilization techniques is an interesting topic in the field of geotechnical engineering and pavements. Nanomaterials and biogeotechnicalbased soil improvement are in high demand, as is the case with the objective of this research which is to determine the effect of the addition of nano lime, nano silica, and chitosan biopolymers to soft clay soil on its mechanical properties. The ratio of additives in this study was taken based on previous research, namely 2% nano lime, 4% nano silica, and 0.1% chitosan biopolymer from shrimp shell waste. Specimen variations consist of initial soil, soil mixed with biopolymers, soil mixed with nanomaterials, and soil mixed with biopolymers and nanomaterials. The mixing method in this study was carried out by mixing the additives according to the percentage of the initial soil dry weight, then water was added to the mixture. Compaction and unconfined compression strength (UCS) tests were conducted on each specimen. The results show that mixing soil with nanomaterials and chitosan provides advantages in mechanical properties. This can be seen from the increase in the UCS value which is up to 11 times that of the initial soil and the increase in the maximum dry density value. Soil stabilization using nanomaterials and chitosan biopolymers has a good impact on the environment. Reducing the ratio of lime in soil stabilization on a project scale can reduce CO₂ emissions during production and the use of chitosan biopolymer additives can reduce marine biota waste, especially invertebrates. [ABSTRACT FROM AUTHOR]