Praseodymium-oxide decorated montmorillonite nanocomposite as a novel admixture for dredged soil stabilisation

Herein a novel nanocomposite, Praseodymium oxide-nano montmorillonite (Pr-nMMT)was fabricated and explored as stabilising admixture for enhancing the strength of dredged soils. The compaction, permeability, direct shear, california bearing ratio (CBR), and unconfined compressive strength (UCS) tests performed on the dredged soil samples collected from the Shalimar site along the Dal Lake Srinagar rendered it unsuitable as construction material and needed stabilisation before using it as a building material. Different percentages of Pr-nMMT (0.25–1%) were used for stabilisation purposes and it revealed that the addition of Pr-nMMT to soil increased maximum dry density (MDD), shear strength parameters (angle of internal friction and cohesion), CBR, and decreased optimum moisture content (OMC), plasticity index, and hydraulic conductivity. The UCS enhanced notably with Pr-nMMT content and increment in curing time. The optimum Pr-nMMT content determined was 0.5% as it demonstrated the maximum value of UCS at 0, 7 and 14 days of curing beyond which the strength showed a declining trend. It was anticipated that Pr-nMMT filled pores between soil particles, therefore resisting sliding among soil particles and thus increasing the strength of treated dredged soil. The results portray Pr-nMMT as an efficient nano admixture for the stabilisation of dredged soil.