Evaluation of Strength Characteristics of Soil Stabilized with Nano Zinc Oxide—Cement Mixes for Low Volume Road Applications

Stabilization of weak soils for road infrastructural applications is a challenging task. Such soils if properly stabilized with innovative technologies, could be adopted in sub-base courses by replacing conventional granular sub-bases for the construction of low-volume roads. In this research, stabilization of silty sand with nano zinc oxide and cement was carried out by adding 1%, 1.5%, and 2% of nano ZnO with 2%, 4% and 6% of cement, respectively. Experiments were organized to examine the effects on proctor compaction, CBR, UCS and Atterberg limit tests. Soaked CBR values of soil doped with 1.5% nano ZnO were substantially enhanced by 158.5%, 311.9%, and 365.3% when treated with 2%, 4% and 6% cement. UCS values were also observed to be drastically improved with the age of curing. Similarly, Atterberg limits on optimized proportion also disclosed a reduction in plasticity characteristics of the soil. Microstructural changes monitored with SEM analysis also supported the experimental results. TCLP test revealed the concentrations of heavy metals in the leachate within permissible limits for the optimized proportion. Strain analysis was carried out by IITPAVE based on four cases of the optimized mix. Soil stabilized with 1.5% nano ZnO and 6% cement was found to be optimal mix and suitable as sub-base material which could fulfill the criteria for chemically stabilized sub-base courses for low volume roads.