Mechanical Behavior of Bitumen and Hot-Mix Asphalt Modified with Zinc Oxide Nanoparticle

Abstract

This study evaluates the effect of zinc oxide nanoparticle (ZnONP) on permanent deformation of modified bitumen. The moisture susceptibility was also evaluated in hot-mix asphalt (HMA) prepared by nano-ZnO modified bitumen. Bitumen modification was conducted using a high shear mixer at contents of 1%, 3%, and 5% by weight. Permanent deformation was evaluated using the G*/sinδ parameter obtained from dynamic shear rheometer (DSR) test results for modified bitumen. Compaction was conducted by a Superpave gyratory compactor, and moisture susceptibility was using the modified Lottman procedure. The dispersion of nanomaterials was analyzed by scanning electron microscopy (SEM). The best performance was obtained by ZnONP 5% modification. The performance grade was determined as PG 64-22 after all modifications. Optimum bitumen content (OBCs) were decreased by modification except the 1% mix (which had the same results as the reference sample). Asphalt mixtures were found to be highly resistant against moisture for all nanomodifications. Lower performance was determined just for the 1% ZnONP modified HMA as compared to the reference sample. After SEM analysis, the dispersion of nanomaterials in the mixture was homogenous. Up to 4 μm agglomeration was displayed in the mix.