Evolution characteristics of the surface texture of the wearing course on asphalt pavement based on accelerated pavement polishing

Abstract

The surface texture of the wearing course on asphalt mixtures is the critical factor affecting the friction behaviors of pavement. The present traditional surface structure evaluation index does not provide the range and the distribution of the texture, and most pavement texture polishing equipment does not represent the actual loading action. In this paper, based on a laser profilometer and a spectral analysis, the mean profile depth (MPD) characterizing the pavement macro-texture is calculated, and the spectral parameter (LTX,1–31.5) characterizing the range and the distribution of the road surface texture is derived. MLS11 equipment is used to polish the wearing course with different design parameters, and the evolution characteristics and influencing factors of the surface texture are studied. The results show that the MPD and the LTX,1–31.5 could distinguish the influence of the oil–stone ratio and the mixture type on the surface macro-structure of the asphalt mixture, and the results of the variation coefficient of the parallel test are within 3.0%. The decay process of the MPD can be divided into three processes (i.e., the relative decay period, the decay period, and the stable period) and six stages. The decay process of the LTX,1–31.5 involves the three processes (the relative stable period, the decay period, and the stable period) and four stages. When the oil–stone ratio increases from 4.4% to 5.4%, the attenuation rates of the MPD and the LTX,1-31.5 decrease. The surface texture of both the GAC-16 and SAS-16 samples are better compared with the AC-16 sample, and the attenuation law of the MPD and the LTX,1-31.5 value is similar. The loss rates of the MPD of the four aggregates are ranked as follows: limestone > diabase > andesite > granite. The loss rates of the LTX,1-31.5 of the four aggregates are ranked as follows: limestone > diabase > granite > andesite.