Surface particle lubrication and wearing mechanism for asphalt pavement with aeolian sand in deserts

Abstract

• Wear and lubrication mechanism of aeolian sand on asphalt pavement was studied. • Rolling-sliding friction exists between tire/road surface with particulate contaminants. • Angularity of the sand accelerates the wear of the asphalt membrane on pavement. • The wearing rate is proposed to evaluate the third body wear effect of aeolian sand. Particulate pollutants have a significant lubricating and abrasive effect on asphalt pavements. In this research, an experimental evaluation using an indoor accelerated wearing apparatus was used to simulate the wearing of Aeolian sand on asphalt pavements in a desert area. The British Pendulum Tester and a 3D scanner have also been used to examine the changes in skid resistance and texture morphology over time. Then, to evaluate the wearing process of sand particles on pavements, the wearing rate was proposed, and ultimately, a prediction model for the pavement with aeolian sand was constructed. The results shows that the wear rates of clean pavement, 50%Ψ and 100%Ψ of sand are 25.6%, 28.6% and 33.8% respectively. In terms of particle lubrication, the pavement is in a mixed lubrication state at 50%Ψ of sand; and in a fluid lubrication state when aeolian sand completely covers asperities of the pavement. From the wearing point of view, tire wearing on clean road is two-body wear; when there is aeolian sand between the tire/road contact interface, it is abrasive wear. The skid resistance prediction model developed by integrating the Pearson Correlation and Ridge Regression methods to identify-five texture indexes (ZMPD, Z Ra , λ q , Z Rs , S dr ) and the British Pendulum Number (BPN) can effectively predict the lubricating and wearing effects of aeolian sand on the pavement.