Calcined bauxite for improving the skid resistance of asphalt mixtures: a state-of-the-art review

Calcined bauxite has attracted increasing attention as a high-performance aggregate for improving the skid resistance of asphalt mixtures because of its high hardness and excellent polishing resistance. This paper presents a systematic review of the use of calcined bauxite in asphalt mixtures to enhance skid resistance. The friction mechanisms, material characteristics, mixture design methods, and major influencing factors are summarized, followed by a discussion of measurement methods, field performance, prediction models, and cost–benefit characteristics. Existing studies show that calcined bauxite exhibits significantly superior physical and mechanical properties compared with conventional natural aggregates, with improvements more than 20%. A single factor does not govern the skid resistance of calcined bauxite asphalt mixtures, but rather the coupled effects of aggregate type, blending ratio, particle size distribution, binder type, and existing pavement conditions. At the same time, blending calcined bauxite with low-grade natural aggregates can provided better long-term friction performance than single aggregate asphalt mixture. It is noted that the cost of calcined bauxite asphalt mixtures can be decreased by using a suitable binder. These findings provide some insights into using calcined bauxite to improve the skid resistance of the asphalt mixture.