Study on the changes of texture characteristic parameters of bauxite clinker re placement asphalt mixtures under accelerated loading

摘要

Compared to other commonly-used aggregates, bauxite clinker has better anti-skid and wear-resistant properties. However, there is little research on the improvement of anti-skid performance of bauxite clinker in asphalt mixture. Therefore, it was necessary to analyze the improvement of the anti-skid performance with the addition of bauxite clinker to asphalt mixtures. In this study, a small accelerated loading (MMLS3) and a laser texture scanner (LTS) were used as the test methods, and the change in the anti-skid performance of asphalt mixtures under different cumulative loads was characterized by using a micro-texture parameter, British pendulum number (BPN), and macro-texture parameters, the mean profile depth (MPD), arithmetic mean deviation (Ra), and skewness (Rsk). The impact of asphalt mixture gradation type, mineral material replacement, the presence or absence of asphalt film, asphalt aging, and other factors on the anti-skid performance texture characterization parameters was analyzed. The research results indicated that bauxite clinker had better anti-skid performance compared to ordinary mineral aggregates under the same gradation conditions. Compared with other texture parameters, Skewness (Rsk) can be used as an index to measure the abrasion degree of asphalt mixture. The change of aggregates with the nominal maximum particle size had a great influence on the anti-skid performance when some rare mineral aggregates were replaced, and the anti-skid performances of asphalt mixtures were significantly improved when pre-flaking the surface of the asphalt film. Also, the thermal aging of the asphalt mixtures showed a negative impact on the anti-skid performance. Finally, an anti-skid performance prediction model has been established by considering the various factors involved.(c) 2021 Elsevier Ltd. All rights reserved.