Journal of Material Sciences & Engineering

New Study on Improved Performance of Paving Asphalts by Crumb Rubber and Polyethylene Modification

Abstract

Mohamed O Sulyman, Maciej Sienkiewicz and Jozef Haponiuk

Conversion of Crumb Rubber Tires (CRT) and waste plastics to functional materials has been shown in this research study as a feasible approach for the improvement of some physical properties of asphalt. The rheological study of the modified asphalt is made through softening point temperature, penetration point, and viscosity tests.
In the present study, CRT and Low Density Polyethylene (LDPE) (plastic wastes) were chosen to be the materials of choice to blend with the virgin asphalt. The reclaimed rubber in the form of powder having a particle size below 0.8 mm was used as an additive to liquid asphalt using the Hot Mix Asphalt Process (HMA) at 180.0 ± 2.0°C with a high-speed stirrer rotating at a speed of 3000 rpm for 60 min. For a consistent mix, the blending operations were performed with different CR and LDPE contents; they were 3.0%, 5.0%, 10.0% and 15.0% by weight. LDPE-CR composite was also added to the virgin asphalt at 1:1, 1:1.5, 1:2, and 1:3 ratios. The results of this research study have indicated that these modified asphalt patterns are characterized by having softening point temperatures and penetration points leading to suitable Penetration Indexes (PI) in comparison with virgin asphalt binder. The viscosity of virgin asphalt was also enhanced with the addition of additives. Best results were obtained when CR, LDPE, and CR-LDPE composite concentrations were attained below 10.0% with most at 5.0%. Determining the number and identities of components in the modified asphalt mixture by Thin Layer Chromatography (TLC) and phase distributions of micrographs from Scanning Electron Microscopy (SEM) was also studied.