The pilot study of skid resistance in plant-mixed dense-graded asphalt concrete with various film thickness of moisture

• Main Authors: Sian-Hao Liang, 梁憲豪
• Other Authors: Yu-Min Su
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/r9rzvv

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 106 === The research objective was to study the skid resistance of plant-mixed dense-graded asphalt concrete with various film thickness of moisture in the laboratory. The 19-mm DGAC mixtures were sampled from Northern Taiwan and test slabs were thereafter compacted into the "450×450×60" -mm wooden frames. A in-house made Wheel-Tracking Polishing Device (WTPD) was assembled with three pneumatic tires to polish surface of slabs with two designated vertical loadings—60 and 95-kg and the 3.52 kg/cm2 (50 psi) of tire pressure. The step-wise polishing efforts—0, 25,000, 50,000, 75,000, 100,000, 125,000, and 150,000-rounds were executed and British Pendulum Tester (BPT), Circular Texture/Track Meter (CTM), and Dynamic Friction Tester (DFT) were employed to evaluate the skid resistance with various film thickness of moisture from 0 (saturated surface dry), 1, 3, to 5-mm. It has to be noted that BPT or CTM were brought to evaluate the unpolished surface under five different testing temperatures from 4, 20, 50, 60, to 70 degree Celsius. The results showed that the WTPD was capable of performing the step-wisely polishing efforts on the surface of compacted slabs and the reduction of skid resistance polished under 95 kg was more than that of polished under 60 kg of vertical loading. When the thin film thickness of moisture increased from 0 to 3-mm, BPN and test results of DFT or DFT20 decreased to 16 to 22-% and 39 to 47-% on the unpolished test slabs, respectively; it was also found both BPN and DFT20 exhibit stable frictional measurements even after 50,000 rounds or more being polished; as such would be possibly attributed to the exposed textures of the aggregates interact well with the rubber sliders of BPT and DFT after the asphalt binders or mastics were removed due to the polishing efforts. In addition, BPN showed inversely in proportional to testing temperatures, while testing results of CTM or Mean Profile Depth (MPD) were not much affected.