Impact of influencing factors on Stribeck curve measurement for bituminous binders

Abstract

Bitumen and aggregates are blended to produce the bituminous mixture at a specific mixing temperature. During the mixing stage, the binder coats the aggregate particles. The efficiency of the coating is influenced by the interfacial friction at the aggregate-binder interface. During the compaction process, the temperature reduces, leading to an increase in viscosity. Such an increase in viscosity also influences the ease with which the mixture can be compacted, and this is again influenced by the friction between the binder-coated aggregate particles. Quantifying the extent of friction, usually characterized by the Stribeck curve, can provide a significant understanding of the compaction mechanics. This study investigates the tribological properties of unmodified binders, focusing on their lubrication characteristics under specific temperatures and normal forces. The study focuses on two typical temperatures, 80 ᵒC, and 160 ᵒC, and two normal forces, such as 3N and 10N, with varying sliding speeds. The Stribeck curves are generated, and the influence of the testing parameters on the generation of the Stribeck curve is discussed in detail.