Abstract:
Pakistan is leading towards a major motorway and highways system, and most of the
roads are flexible pavements that have a higher susceptibility to Fatigue and Rutting.
The utilization of Nano materials in Hot Mix Asphalt (HMA) can significantly improve
the performance indicators in the form of extension in pavement service life and
decrease pavement distresses. The Nano materials reinforcement of HMA can enhance
pavement performance indicators, including low and high-temperature dynamic
modulus and stability and enhancement in rut resistance and stiffness modulus. Nano
Materials modified is a suitable solution to improve the mechanical properties of HMA.
The current study objectives focus on the experimental investigation of Nano Materials
such as Carbon Nano Tubes (CNT) and Nano Clay (NC) applicability in HMA. CNT
and NC percentages used in HMA to the weight of bitumen are 0.5%, 1.5%, 2.5% and
2%, 4%, 6%, 8%. Conventional and Nano material modified asphalt mixes were
subjected to performance tests such as SPT, Dynamic Stability and Rutting, Tensile
Strength Ratio (TSR), and Resilient Modulus (MR) using UTM-25. Results have
indicated that the addition of CNT and NC has improved HMA properties such as
enhancement in dynamic modulus and dynamic stability and improves stiffness, rut
resistance, and moisture resistance. It has been observed that 1.5% CNT with 6% NC
content by weight of bitumen in asphalt mixtures outperformed other CNT and NC
percentages. Moreover, Dynamic stability and Rut resistance have been improved by
820% and 64.7%, respectively, while resilient modulus increased by 309% and
moisture susceptibility has been reduced by 22.26%, respectively. Overall, the asphalt
mixtures with 1.5% CNT with 6% NC content has the best results.
