19-10-2017, 12:22 PM
Plastics were crushed and mixed with the in-situ bitumen, with a shear mixer in a temperature range of 160 ° C-170 ° C. The basic rheological parameters such as penetration, ring softening point and the ball and the viscosity tests were used to determine the changes resulting from the base bitumen. FTIR spectroscopy was also used to study the chemical functionalities present in the bituminous compound. It was found that the properties of unmodified bitumen were enhanced with changes in the rheological properties of polymer modified bitumen (PMB). It was observed that the polypropylene polymer showed a profound effect on homogeneity and compatibility with a slight linear increase in viscosity, softening and penetration values versus relatively high changes for the modified HDPE bitumen. The viscosity of the unmodified bitumen was improved with the addition of the polymers and a thixotropic effect was observed for HDPE and PP at 60 ° C. For all modified binders prepared, the penetration values decrease as the polymer-bitumen ratio increases while the softening temperature generally increases as the ratio of the polymer increases. The most compatible and incompatible blends for HDPE were respectively observed at 2% and 3% polymer loading. The most improved homogeneous blend is achieved with PP at a polymer load of 3%. Three prominent peaks were identified in the unmodified bitumen spectrum, occurring in the IR frequency range of 3000-2850 cm -1, typical of asymmetric and asymmetric aliphatic stretches of CH in alkanes. CH 2 and CH 3 curves were also observed at the characteristic frequencies of 1465 cm -1 and 1375 cm -1, respectively. A low intensity peak was observed within the range of 2400 cm-1-2100 cm -1, indicating the presence of a very weak group -CC- or -CN with an absorbance of 0.12. The use of waste plastics in binder modification has the advantage of an inexpensive and efficient means to improve the performance characteristics of the conventional bitumen binder and is an alternative way of using plastic waste.