The Microstructure and Thermochemical Evaluation Properties of Polypropylene-Modified Asphalt Concrete for Enhanced Performance

In the road construction industry, efforts are being made to incorporate polypropylene with polymer properties into asphalt mixtures to improve the mechanical performance of the pavement layers and address the environmental demands caused by the significant accumulation of plastic waste. The impact of recycled polypropylene on the chemical, thermal, rheological, and microstructural characteristics of the specified asphalt mixture is the main emphasis of this study, which also identifies how each attribute enhances performance. The polypropylene and modified bitumen were characterised using thermogravimetric, dynamic shear rheometer, rotational viscosity, penetration, softening point, flash and fire point, ductility, water-in-bitumen, viscosity, x-ray diffraction, and x-ray fluorescence. The asphalt concrete was produced with varying proportions of polypropylene at 5%, 10%, 15%, and 20%, respectively. Moreover, the polypropylene-modified asphalt concrete was analysed to determine its microstructures. It has been observed that polypropylene enhances the physical, chemical, thermal, and rheological properties of bitumen. The Marshall stability result showed that the values obtained complied with Nigeria's general road and bridge specifications 1997 and Asphalt Institute 1997 standards. These results concluded that polypropylene could improve and strengthen flexible pavement and reduce environmental hazards.