Enhanced Pavement Performance and Improved Stability of Asphalt and Recycled Plastic Blends Modified by Exfoliated Clay Nanoplatelets

Abstract

The inclusion of recycled plastics into hot-mix asphalt is highly desirable for improved pavement performance. In this study, the need for enhanced compatibility between the components and increased mechanical performance of asphalt (AS) and polyethylene (PE) blends was addressed through the use of dispersed/exfoliated nanoclays (NC). Fourier-transform infrared (FTIR) spectroscopy showed evidence of new chemical interactions of the dispersed NC-d within the AS/PE matrix, suggesting a better-blended phase morphology. The layered silicate plate-like morphology of dispersed/exfoliated NC, identified by scanning electron microscopy, SEM, observations, promotes a greater adhesion between asphalt and polyethylene, leading to significant enhancements in all mechanical properties of viscoelastic AS/PE/NC-d blend. Indirect tensile (IDT) strength, uniaxial compression, and compression fatigue tests were performed on AS/PE blends modified by “as received” and dispersed/exfoliated NCs. The effective modification of the AS/PE blend with the dispersed/exfoliated NC-d is demonstrated by a significant improvement in IDT strength (40%), cracking tolerance index (26%), failure energy (22%), compressive strength (42%), and dynamic modulus (44%).