INVESTIGATION OF CARBON NANO TUBE EFFECT ON SUBGRADE SOIL PROPERTIES

Anuj Tiwari; Neero Gumsar Sorum

doi:10.4314/njt.2026.5201

Authors

A. Tiwari North Eastern Regional Institute of Science and Technology, Department of Civil Engineering, Nirjuli, Arunachal Pradesh, India
N. G. Sorum North Eastern Regional Institute of Science and Technology, Department of Civil Engineering, Nirjuli, Arunachal Pradesh, India

DOI:

https://doi.org/10.4314/njt.2026.5201

Keywords:

Soil Stabilization, Nano reinforcement, Pavement Engineering, Carbon Nano Tubes (CNTs), Sustainable Infrastructure

Abstract

This study investigates the effectiveness of Multi-Walled Carbon Nanotubes (CNTs) in enhancing the geotechnical properties of weak subgrade soil for pavement applications. Poorly graded sand (SP) sourced from Naharlagun, Arunachal Pradesh, India, was treated with CNTs at 0.2%, 0.4%, and 0.6% by dry weight. A holistic evaluation of unconfined compressive strength (UCS), California Bearing Ratio (CBR), permeability, compaction, and shear strength was carried out marking the first comprehensive assessment of CNT-stabilized SP soil from Arunachal Pradesh. The results demonstrated substantial mechanical benefits, with UCS increasing by approximately 2.5-3 times after 28 days of curing at 0.6% CNT. CBR values also improved for both soaked and unsoaked conditions, indicating enhanced load-bearing capacity suitable for pavement layers. Additionally, a reduction of over 50% in permeability confirmed improved resistance to moisture ingress, which is essential for long-term subgrade performance in high-rainfall regions. Statistical analysis using ANOVA verified that the improvements in UCS and CBR were highly significant (p < 0.001), while compaction characteristics remained largely unchanged. These enhancements are attributed to nano-scale effects such as void filling and inter-particle bonding. Overall, CNTs show strong potential as a sustainable, low-dosage reinforcement material for moisture-sensitive subgrades in challenging terrains.

Author Biography

N. G. Sorum, North Eastern Regional Institute of Science and Technology, Department of Civil Engineering, Nirjuli, Arunachal Pradesh, India

Associate Professor, Department of Civil Engineering

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