The effects of different dusty aggregate on bituminous hot mixtures

Abstract

Adhesion between aggregate and bitumen is an important parameter of the performance of bituminous hot mix pavements. Dust on the aggregate surface adversely affects bituminous hot mix pavement performance and leads to some types of deterioration, such as raveling, rutting, stripping, and segregation, decreasing long-term pavement performance. The main objective of this study is to determine the effects of different dust contents of the aggregate surface on the bituminous hot mixture. Two separate aggregate specimens with contents of three different dusts were used to produce bituminous hot mixture specimens. Specific gravity, unit weight, gradation analysis, water absorption, Los Angeles abrasion, aggregate impact, freezing and thawing, Nicholson stripping, and Vialit adhesion tests were performed as aggregate tests, whereas Marshall stability and flow, Marshall mechanical immersion, and indirect tensile tests were performed as bituminous hot mixture tests. The study results show that dust content on the aggregate surface weakens adhesion, leading to the gradual deterioration of the characteristics of the hot bituminous mixtures. Because dust contents on the aggregate surface can vary according to the aggregate type, the progression of the deterioration of bituminous hot mixtures can also vary.

Keywords

• adhesion
• aggregate
• bituminous hot mixtures
• dust