Study on Road Performances of Ultra-thin Wearing Layer Small Particle Size Asphalt Mixture

Abstract

In order to find out that if it is available to apply the asphalt mixture with small particle size and large porosity to the ultra-thin wearing layer, a kind of open-graded asphalt mixture whose nominal maximum aggregate size is 4.75mm and void ratio is greater than 20% is designed in this article. The rutting test, low-temperature bending test, freeze-thaw split test, pendulum friction coefficient test, manual sand patch test and permeability test are conducted to evaluate the road performance and surface behavior like high-temperature stability, low-temperature, water stability, friction and permeability. The test results shows that the asphalt mixture’s 60℃ dynamic stability is 8201 times /mm, ultimate bending strain is 2896 μe, the residual strength ratio of freeze-thaw split is 83.94%, BPN is 69, the texture depth is 0.71mm, and water permeability coefficient is 6857mL/min. It can be concluded that the asphalt mixture with small particle sized aggregate and large porosity has good road performance, whose high-temperature stability, anti-skid performance and drainage performance are excellent. Compared with road performance of OGFC-13, small particle asphalt mixture can also be used as ultra-thin wearing course.