Towards the Use of Waste Expanded Polystyrene as Potential Modifier for Flexible Road Pavements

Abstract

Expanded polystyrene (EPS) or Styrofoam is popularly used in the industry, as packaging and construction materials, as well as in household appliances. Nevertheless, its waste (WEPS) causes residual solid waste problem. This study aimed at utilizing WEPS as performance enhancing additives for road paving applications. One base AP-5 asphalt was mixed with various percentages of WEPS (e.g., 0, 3, 6, 9 wt. %). The properties of unmodified and WEPS-modified asphalts were assessed through Fourier transform-infrared spectroscopy (FT-IR), thin layer chromatography-ionization detection (TLC-FID), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Findings disclosed that WEPS addition increased the resins concentration in the asphalt matrix, but did not affect its crystalline phase structure. SEM revealed that WEPS was compatible with asphalt binder. TGA and DSC analyses demonstrated that the thermal properties of blends behaved differently in response to WEPS treatment. Taken as a whole, the present research suggests that WEPS could be used as a bitumen modifier; however, further work is needed to add more credibility to this claim