Geotechnical Benign Characterization of Nano-amended CLS Stabilized Soil

Nanomaterials are gaining acceptance in the geotechnical and geoenvironmental engineering fields due to their non-toxic nature and less energy required for production. This paper deals with the effect of iron oxide nanoparticles (nano-Fe2O3) inclusion along with calcium lignosulfonate (CLS) as a binder in enhancing the strength characteristics of locally available soil. CLS acts as an initiator and enhances the interaction of nanoparticles with soil. The different proportions of nano-Fe2O3 and CLS considered for the tests were 0.1%–0.3% and 1%–3%, respectively. Compaction tests and unconfined compression strength tests were carried out at different proportions of nano-Fe2O3 and CLS dosages, blended individually and in combination. The desired values of maximum dry density and optimum moisture content were obtained for a combination of 0.2% nano-Fe2O3 and 2% CLS. Unconfined compressive strength (UCS) test was conducted for samples cured for 7, 14, and 28 days, which were mixed with different proportions of nano-Fe2O3, and CLS showed a tremendous improvement in soil strength. There was a significant improvement in the 28 days strength from 183.4 kPa to a maximum of 496.5 kPa. The mechanism responsible for the improvement in the strength characteristics was confirmed by the SEM images of the stabilized soil samples obtained from UCS tests.