Performance augmentation of asphalt binder with multi-walled carbon nanotubes

Abstract

This aim of this research was to enhance the performance of asphalt binder using multi-walled carbon nanotubes (MWCNTs) and wet mixing. Five asphaltic binder compositions were prepared with varying amounts of MWCNT additions in the range 0–1.50 %w/w. The binder performance was evaluated through an investigation of the basic viscoelastic properties, rheological characteristics and moisture susceptibility. Viscoelastic properties were assessed by penetration, softening point, ductility and dynamic shear rheometer tests. The rolling bottle test was used for moisture sensitivity analysis. Fourier transmission infrared spectroscopy was used to check the chemical reactivity of various solvents with the asphalt binder and scanning electron microscopy was used to observe the level of MWCNT dispersion in the mixtures. Samples were also assessed for storage stability and a safety analysis was carried out to determine selection of an appropriate carrier solvent. The results showed improvements in the permanent deformation and stripping resistance of the binders. The addition of MWCNTs at 1.5 %w/w of asphalt binder reduced the penetration by 14.4%, increased the softening point by and 10.2% and increased the ductility by 40%. Furthermore, considerable improvements in the phase angle and dynamic shear modulus were observed, accompanied by a 50% reduction in stripping after 24 h.