Influence of Aggregate Types on the Long-Term Skid Resistance of Porous Asphalt Mixture Based on the Laboratory MMLS

Abstract

In order to study the influence of aggregate types on the long-term skid resistance of asphalt pavement, six different types of aggregates such as arkose, red sandstone, limestone, basalt, diabase, and granite were selected. The one-third-scale model mobile load simulator (MMLS) was used to conduct wear tests on porous asphalt mixtures (PA-13) prepared with six types of aggregates. The antiskid performance indicators of British pendulum number (BPN) and macrotexture depth (MTD) of the mixture were measured under different loading times. After wear, the microtexture, hardness, and mineral composition of the aggregates were tested using a laser scanning confocal microscope (LSCM), Vickers hardness tester (VHT), and X-ray diffractometer (XRD) to reveal the mechanism of antiskid durability of different aggregates. The results show that the asphalt mixture prepared with sandstone and granite aggregate has the best antiskid durability, and the attenuation rate and loss rate of antiskid performance are the smallest. The micro-texture of the worn aggregates shows that sandstone and granite are the roughest, whereas limestone is the smoothest. The correlation between texture index of Rsk and the antiskid performance is the greatest. The more complex the mineral composition of the aggregate and the greater the Vickers hardness, the better the antiskid durability of the asphalt mixture.