Pavement Recycling with Asphalt Dust and 3% Hydraulic Cement

Abstract

Pavement recycling is one method for improving road construction by reusing the existing pavement materials obtained from road resurfacing in damaged sections. Generally, cement is added as a binder to increase the strength of the recycled pavement materials. Additionally, the production process of asphalt concrete generates asphalt dust, which is an economically non-valuable byproduct and leads to additional disposal costs. This research explores the innovative approach of incorporating asphalt dust with cement to enhance the mechanical strength and promote the sustainability of pavement recycling. Additionally, asphalt dust, a waste product from the production of asphalt concrete, can be mixed with cement. This combination enhances the strength of recycled pavement materials and contributes to the sustainability of the recycling process. This research focuses on cement used in recycling existing pavement materials, aiming for a cement content of only 3% by the dry weight of the aggregate (%). The tests were conducted under 5 different conditions: 1) reclaimed asphalt pavement mixed with crushed rock, 2) reclaimed asphalt pavement mixed with crushed rock and 3% cement, 3) reclaimed asphalt pavement mixed with crushed rock, 3% cement and 10% asphalt dust, 4) reclaimed asphalt pavement mixed with crushed rock, 3% cement and 20% asphalt dust and 5) reclaimed asphalt pavement mixed with crushed rock, 3% cement and 30% asphalt dust. These samples were tested under compaction, unconfined compressive strength, and indirect tensile strength tests. The results showed that samples of reclaimed asphalt pavement mixed with crushed rock, 3% cement, 10% and 20% asphalt dust, performed better in both the unconfined compressive strength and indirect tensile strength tests compared to the sample of reclaimed asphalt pavement mixed with crushed rock or reclaimed asphalt pavement mixed with crushed rock and
3% cement. Moreover, it was found that the optimal amount of asphalt dust for improving the quality of recycled pavement materials is between 10% and 20% by the dry weight of the aggregate.