Development of Open-Graded Asphalt Mixtures with Recycled Aggregate and Fly Ash

Abstract: The open-graded asphalt mixtures have high porosity to improves to reduces storm water runoff from pavements and improve the skid resistance. However, it has low durability. This study intends to investigate and evaluate the replacement of natural aggregate in porous asphalt mixtures with locally waste materials. Waste materials namely recycled aggregate (RA) and fly ash were obtained from Najran region. Nowadays, more sustainable approaches should be applied to replace natural aggregates. Mixtures of different combinations of recycled aggregate (for coarse aggregate replacement) and fly ash (for fine aggregate replacement) were prepared in the laboratory and tested. Two aggregate open gradations of different nominal maximum aggregate sizes (NMASs) (i.e., 4.75 and 12.5 mm), one asphalt binder, and granite aggregates were included in the study to prepare the open-graded asphalt mixture specimens. Coarse and fine natural aggregates were replaced with recycled aggregate and fly ash at various percentages from 0 to 20% as Coarse aggregates and from 0% to 5% as fine aggregates. Experimental approved was used to evaluate the air void, strength and resistance to raveling. Preliminary result exhibited promising result in terms of resistance to raveling. This study will help to disposal the waste materials (recycled aggregate and fly ash) in Najran region.